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  <link:roleRef roleURI="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="simple" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedLabel" />
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    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_ProceedsFromSaleOfConvertiblePreferredStockNetOfIssuanceCosts" xlink:label="ProceedsFromSaleOfConvertiblePreferredStockNetOfIssuanceCosts" xlink:title="ProceedsFromSaleOfConvertiblePreferredStockNetOfIssuanceCosts" />
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ProceedsFromSaleOfConvertiblePreferredStockNetOfIssuanceCosts" xlink:to="label_ProceedsFromSaleOfConvertiblePreferredStockNetOfIssuanceCosts" xlink:title="label: ProceedsFromSaleOfConvertiblePreferredStockNetOfIssuanceCosts to label_ProceedsFromSaleOfConvertiblePreferredStockNetOfIssuanceCosts" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ProceedsFromSaleOfConvertiblePreferredStockNetOfIssuanceCosts_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ProceedsFromSaleOfConvertiblePreferredStockNetOfIssuanceCosts" xml:lang="en-US" id="label_ProceedsFromSaleOfConvertiblePreferredStockNetOfIssuanceCosts_2">Proceeds from sale of convertible preferred stock, net of issuance costs</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ProceedsFromSaleOfConvertiblePreferredStockNetOfIssuanceCosts" xlink:to="label_ProceedsFromSaleOfConvertiblePreferredStockNetOfIssuanceCosts_2" xlink:title="label: ProceedsFromSaleOfConvertiblePreferredStockNetOfIssuanceCosts to label_ProceedsFromSaleOfConvertiblePreferredStockNetOfIssuanceCosts" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ProceedsFromSaleOfConvertiblePreferredStockNetOfIssuanceCosts_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_ProceedsFromSaleOfConvertiblePreferredStockNetOfIssuanceCosts" xml:lang="en-US" id="label_ProceedsFromSaleOfConvertiblePreferredStockNetOfIssuanceCosts_3">The cash inflow from sale of preferred stock identified as being convertible into another form of financial instrument, typically the entity's common stock, net of issuance costs.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ProceedsFromSaleOfConvertiblePreferredStockNetOfIssuanceCosts" xlink:to="label_ProceedsFromSaleOfConvertiblePreferredStockNetOfIssuanceCosts_3" xlink:title="label: ProceedsFromSaleOfConvertiblePreferredStockNetOfIssuanceCosts to label_ProceedsFromSaleOfConvertiblePreferredStockNetOfIssuanceCosts" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_SeriesA2ConvertiblePreferredStockMember" xlink:label="SeriesA2ConvertiblePreferredStockMember" xlink:title="SeriesA2ConvertiblePreferredStockMember" />
    <link:label xlink:type="resource" xlink:label="label_SeriesA2ConvertiblePreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_SeriesA2ConvertiblePreferredStockMember" xml:lang="en-US" id="label_SeriesA2ConvertiblePreferredStockMember">Represents information pertaining to the type or class of series A-2 convertible preferred stock. Convertible redeemable preferred stock possess conversion and redemption features. The stock has redemption features which are outside the control of the issuer.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesA2ConvertiblePreferredStockMember" xlink:to="label_SeriesA2ConvertiblePreferredStockMember" xlink:title="label: SeriesA2ConvertiblePreferredStockMember to label_SeriesA2ConvertiblePreferredStockMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesA2ConvertiblePreferredStockMember_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SeriesA2ConvertiblePreferredStockMember" xml:lang="en-US" id="label_SeriesA2ConvertiblePreferredStockMember_2">Series A2 Convertible Preferred Stock [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesA2ConvertiblePreferredStockMember" xlink:to="label_SeriesA2ConvertiblePreferredStockMember_2" xlink:title="label: SeriesA2ConvertiblePreferredStockMember to label_SeriesA2ConvertiblePreferredStockMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesA2ConvertiblePreferredStockMember_3" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SeriesA2ConvertiblePreferredStockMember" xml:lang="en-US" id="label_SeriesA2ConvertiblePreferredStockMember_3">Series A-2 Convertible Preferred Shares</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesA2ConvertiblePreferredStockMember" xlink:to="label_SeriesA2ConvertiblePreferredStockMember_3" xlink:title="label: SeriesA2ConvertiblePreferredStockMember to label_SeriesA2ConvertiblePreferredStockMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesA2ConvertiblePreferredStockMember_4" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_SeriesA2ConvertiblePreferredStockMember" xml:lang="en-US" id="label_SeriesA2ConvertiblePreferredStockMember_4">Series A-2 preferred stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesA2ConvertiblePreferredStockMember" xlink:to="label_SeriesA2ConvertiblePreferredStockMember_4" xlink:title="label: SeriesA2ConvertiblePreferredStockMember to label_SeriesA2ConvertiblePreferredStockMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_SeriesA3ConvertiblePreferredStockMember" xlink:label="SeriesA3ConvertiblePreferredStockMember" xlink:title="SeriesA3ConvertiblePreferredStockMember" />
    <link:label xlink:type="resource" xlink:label="label_SeriesA3ConvertiblePreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SeriesA3ConvertiblePreferredStockMember" xml:lang="en-US" id="label_SeriesA3ConvertiblePreferredStockMember">Series A-3 Convertible Preferred Shares</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesA3ConvertiblePreferredStockMember" xlink:to="label_SeriesA3ConvertiblePreferredStockMember" xlink:title="label: SeriesA3ConvertiblePreferredStockMember to label_SeriesA3ConvertiblePreferredStockMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesA3ConvertiblePreferredStockMember_2" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_SeriesA3ConvertiblePreferredStockMember" xml:lang="en-US" id="label_SeriesA3ConvertiblePreferredStockMember_2">Represents information pertaining to the type or class of series A-3 convertible preferred stock. Convertible redeemable preferred stock possess conversion and redemption features. The stock has redemption features which are outside the control of the issuer.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesA3ConvertiblePreferredStockMember" xlink:to="label_SeriesA3ConvertiblePreferredStockMember_2" xlink:title="label: SeriesA3ConvertiblePreferredStockMember to label_SeriesA3ConvertiblePreferredStockMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesA3ConvertiblePreferredStockMember_3" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_SeriesA3ConvertiblePreferredStockMember" xml:lang="en-US" id="label_SeriesA3ConvertiblePreferredStockMember_3">Series A-3 preferred stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesA3ConvertiblePreferredStockMember" xlink:to="label_SeriesA3ConvertiblePreferredStockMember_3" xlink:title="label: SeriesA3ConvertiblePreferredStockMember to label_SeriesA3ConvertiblePreferredStockMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesA3ConvertiblePreferredStockMember_4" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SeriesA3ConvertiblePreferredStockMember" xml:lang="en-US" id="label_SeriesA3ConvertiblePreferredStockMember_4">Series A3 Convertible Preferred Stock [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesA3ConvertiblePreferredStockMember" xlink:to="label_SeriesA3ConvertiblePreferredStockMember_4" xlink:title="label: SeriesA3ConvertiblePreferredStockMember to label_SeriesA3ConvertiblePreferredStockMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_SeriesA4ConvertiblePreferredStockMember" xlink:label="SeriesA4ConvertiblePreferredStockMember" xlink:title="SeriesA4ConvertiblePreferredStockMember" />
    <link:label xlink:type="resource" xlink:label="label_SeriesA4ConvertiblePreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SeriesA4ConvertiblePreferredStockMember" xml:lang="en-US" id="label_SeriesA4ConvertiblePreferredStockMember">Series A4 Convertible Preferred Stock [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesA4ConvertiblePreferredStockMember" xlink:to="label_SeriesA4ConvertiblePreferredStockMember" xlink:title="label: SeriesA4ConvertiblePreferredStockMember to label_SeriesA4ConvertiblePreferredStockMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesA4ConvertiblePreferredStockMember_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SeriesA4ConvertiblePreferredStockMember" xml:lang="en-US" id="label_SeriesA4ConvertiblePreferredStockMember_2">Series A-4 Convertible Preferred Shares</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesA4ConvertiblePreferredStockMember" xlink:to="label_SeriesA4ConvertiblePreferredStockMember_2" xlink:title="label: SeriesA4ConvertiblePreferredStockMember to label_SeriesA4ConvertiblePreferredStockMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesA4ConvertiblePreferredStockMember_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_SeriesA4ConvertiblePreferredStockMember" xml:lang="en-US" id="label_SeriesA4ConvertiblePreferredStockMember_3">Represents information pertaining to the type or class of series A-4 convertible preferred stock. Convertible redeemable preferred stock possess conversion and redemption features. The stock has redemption features which are outside the control of the issuer.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesA4ConvertiblePreferredStockMember" xlink:to="label_SeriesA4ConvertiblePreferredStockMember_3" xlink:title="label: SeriesA4ConvertiblePreferredStockMember to label_SeriesA4ConvertiblePreferredStockMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesA4ConvertiblePreferredStockMember_4" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_SeriesA4ConvertiblePreferredStockMember" xml:lang="en-US" id="label_SeriesA4ConvertiblePreferredStockMember_4">Series A-4 preferred stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesA4ConvertiblePreferredStockMember" xlink:to="label_SeriesA4ConvertiblePreferredStockMember_4" xlink:title="label: SeriesA4ConvertiblePreferredStockMember to label_SeriesA4ConvertiblePreferredStockMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_SeriesAConvertiblePreferredStockMember" xlink:label="SeriesAConvertiblePreferredStockMember" xlink:title="SeriesAConvertiblePreferredStockMember" />
    <link:label xlink:type="resource" xlink:label="label_SeriesAConvertiblePreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SeriesAConvertiblePreferredStockMember" xml:lang="en-US" id="label_SeriesAConvertiblePreferredStockMember">Series A Convertible Preferred Shares</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesAConvertiblePreferredStockMember" xlink:to="label_SeriesAConvertiblePreferredStockMember" xlink:title="label: SeriesAConvertiblePreferredStockMember to label_SeriesAConvertiblePreferredStockMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesAConvertiblePreferredStockMember_2" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_SeriesAConvertiblePreferredStockMember" xml:lang="en-US" id="label_SeriesAConvertiblePreferredStockMember_2">Series A preferred stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesAConvertiblePreferredStockMember" xlink:to="label_SeriesAConvertiblePreferredStockMember_2" xlink:title="label: SeriesAConvertiblePreferredStockMember to label_SeriesAConvertiblePreferredStockMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesAConvertiblePreferredStockMember_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_SeriesAConvertiblePreferredStockMember" xml:lang="en-US" id="label_SeriesAConvertiblePreferredStockMember_3">Represents information pertaining to the type or class of series A convertible preferred stock. Convertible redeemable preferred stock possess conversion and redemption features. The stock has redemption features which are outside the control of the issuer.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesAConvertiblePreferredStockMember" xlink:to="label_SeriesAConvertiblePreferredStockMember_3" xlink:title="label: SeriesAConvertiblePreferredStockMember to label_SeriesAConvertiblePreferredStockMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesAConvertiblePreferredStockMember_4" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SeriesAConvertiblePreferredStockMember" xml:lang="en-US" id="label_SeriesAConvertiblePreferredStockMember_4">Series A Convertible Preferred Stock [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesAConvertiblePreferredStockMember" xlink:to="label_SeriesAConvertiblePreferredStockMember_4" xlink:title="label: SeriesAConvertiblePreferredStockMember to label_SeriesAConvertiblePreferredStockMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_SeriesB1ConvertiblePreferredStockMember" xlink:label="SeriesB1ConvertiblePreferredStockMember" xlink:title="SeriesB1ConvertiblePreferredStockMember" />
    <link:label xlink:type="resource" xlink:label="label_SeriesB1ConvertiblePreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_SeriesB1ConvertiblePreferredStockMember" xml:lang="en-US" id="label_SeriesB1ConvertiblePreferredStockMember">Represents information pertaining to the type or class of series B-1 convertible preferred stock. Convertible redeemable preferred stock possess conversion and redemption features. The stock has redemption features which are outside the control of the issuer.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesB1ConvertiblePreferredStockMember" xlink:to="label_SeriesB1ConvertiblePreferredStockMember" xlink:title="label: SeriesB1ConvertiblePreferredStockMember to label_SeriesB1ConvertiblePreferredStockMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesB1ConvertiblePreferredStockMember_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SeriesB1ConvertiblePreferredStockMember" xml:lang="en-US" id="label_SeriesB1ConvertiblePreferredStockMember_2">Series B-1 Convertible Preferred Shares</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesB1ConvertiblePreferredStockMember" xlink:to="label_SeriesB1ConvertiblePreferredStockMember_2" xlink:title="label: SeriesB1ConvertiblePreferredStockMember to label_SeriesB1ConvertiblePreferredStockMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesB1ConvertiblePreferredStockMember_3" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_SeriesB1ConvertiblePreferredStockMember" xml:lang="en-US" id="label_SeriesB1ConvertiblePreferredStockMember_3">Series B-1 Preferred Stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesB1ConvertiblePreferredStockMember" xlink:to="label_SeriesB1ConvertiblePreferredStockMember_3" xlink:title="label: SeriesB1ConvertiblePreferredStockMember to label_SeriesB1ConvertiblePreferredStockMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesB1ConvertiblePreferredStockMember_4" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SeriesB1ConvertiblePreferredStockMember" xml:lang="en-US" id="label_SeriesB1ConvertiblePreferredStockMember_4">Series B1 Convertible Preferred Stock [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesB1ConvertiblePreferredStockMember" xlink:to="label_SeriesB1ConvertiblePreferredStockMember_4" xlink:title="label: SeriesB1ConvertiblePreferredStockMember to label_SeriesB1ConvertiblePreferredStockMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_SeriesBConvertiblePreferredStockMember" xlink:label="SeriesBConvertiblePreferredStockMember" xlink:title="SeriesBConvertiblePreferredStockMember" />
    <link:label xlink:type="resource" xlink:label="label_SeriesBConvertiblePreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_SeriesBConvertiblePreferredStockMember" xml:lang="en-US" id="label_SeriesBConvertiblePreferredStockMember">Represents information pertaining to the type or class of series B convertible preferred stock. Convertible redeemable preferred stock possess conversion and redemption features. The stock has redemption features which are outside the control of the issuer.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesBConvertiblePreferredStockMember" xlink:to="label_SeriesBConvertiblePreferredStockMember" xlink:title="label: SeriesBConvertiblePreferredStockMember to label_SeriesBConvertiblePreferredStockMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesBConvertiblePreferredStockMember_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SeriesBConvertiblePreferredStockMember" xml:lang="en-US" id="label_SeriesBConvertiblePreferredStockMember_2">Series B Convertible Preferred Stock [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesBConvertiblePreferredStockMember" xlink:to="label_SeriesBConvertiblePreferredStockMember_2" xlink:title="label: SeriesBConvertiblePreferredStockMember to label_SeriesBConvertiblePreferredStockMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesBConvertiblePreferredStockMember_3" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SeriesBConvertiblePreferredStockMember" xml:lang="en-US" id="label_SeriesBConvertiblePreferredStockMember_3">Series B Convertible Preferred Shares</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesBConvertiblePreferredStockMember" xlink:to="label_SeriesBConvertiblePreferredStockMember_3" xlink:title="label: SeriesBConvertiblePreferredStockMember to label_SeriesBConvertiblePreferredStockMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesBConvertiblePreferredStockMember_4" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_SeriesBConvertiblePreferredStockMember" xml:lang="en-US" id="label_SeriesBConvertiblePreferredStockMember_4">Series B preferred stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesBConvertiblePreferredStockMember" xlink:to="label_SeriesBConvertiblePreferredStockMember_4" xlink:title="label: SeriesBConvertiblePreferredStockMember to label_SeriesBConvertiblePreferredStockMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateIntrinsicValueAbstract" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateIntrinsicValueAbstract" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateIntrinsicValueAbstract" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateIntrinsicValueAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateIntrinsicValueAbstract" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateIntrinsicValueAbstract">Share based Compensation Arrangement by Share based Payment Award Aggregate Intrinsic Value [Abstract]</link:label>
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    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedAnnual" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedAnnual" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedAnnual" />
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    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedFrom2010StockIncentivePlan" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedFrom2010StockIncentivePlan" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedFrom2010StockIncentivePlan" />
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    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedFrom2010StockIncentivePlan_2" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedFrom2010StockIncentivePlan" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedFrom2010StockIncentivePlan_2">Represents the number of additional shares authorized for issuance under the 2010 Stock Incentive Plan.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedFrom2010StockIncentivePlan" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedFrom2010StockIncentivePlan_2" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedFrom2010StockIncentivePlan to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedFrom2010StockIncentivePlan" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedFrom2010StockIncentivePlan_3" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedFrom2010StockIncentivePlan" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedFrom2010StockIncentivePlan_3">Share Based Compensation Arrangement by Share Based Payment Award Number of Additional Shares Authorized from 2010 Stock Incentive Plan</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedFrom2010StockIncentivePlan" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedFrom2010StockIncentivePlan_3" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedFrom2010StockIncentivePlan to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedFrom2010StockIncentivePlan" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_AmendmentDescription" xlink:label="AmendmentDescription" xlink:title="AmendmentDescription" />
    <link:label xlink:type="resource" xlink:label="label_AmendmentDescription" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AmendmentDescription" xml:lang="en-US" id="label_AmendmentDescription">Amendment Description</link:label>
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    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedInPercentageAnnual" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedInPercentageAnnual" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedInPercentageAnnual" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedInPercentageAnnual" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedInPercentageAnnual" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedInPercentageAnnual">Share-based Compensation Arrangement by Share-based Payment Award Number of Additional Shares Authorized in Percentage Annual</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedInPercentageAnnual" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedInPercentageAnnual" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedInPercentageAnnual to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedInPercentageAnnual" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedInPercentageAnnual_2" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedInPercentageAnnual" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedInPercentageAnnual_2">Represents the annual increase in percentage of common stock, which is used to issue additional shares authorized for issuance under the established share-based compensation plan.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedInPercentageAnnual" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedInPercentageAnnual_2" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedInPercentageAnnual to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedInPercentageAnnual" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedInPercentageAnnual_3" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedInPercentageAnnual" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedInPercentageAnnual_3">Percentage applied to the outstanding shares as annual increase in the number of shares authorized for issuance</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedInPercentageAnnual" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedInPercentageAnnual_3" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedInPercentageAnnual to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorizedInPercentageAnnual" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_AmendmentFlag" xlink:label="AmendmentFlag" xlink:title="AmendmentFlag" />
    <link:label xlink:type="resource" xlink:label="label_AmendmentFlag" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AmendmentFlag" xml:lang="en-US" id="label_AmendmentFlag">Amendment Flag</link:label>
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    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_ShareBasedCompensationArrangementByShareBasedPaymentAwardRestrictedStockExerciseOfOptionsNonvestedNumber" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardRestrictedStockExerciseOfOptionsNonvestedNumber" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardRestrictedStockExerciseOfOptionsNonvestedNumber" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardRestrictedStockExerciseOfOptionsNonvestedNumber" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardRestrictedStockExerciseOfOptionsNonvestedNumber" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardRestrictedStockExerciseOfOptionsNonvestedNumber">Share Based Compensation Arrangement by Share Based Payment Award Restricted Stock Exercise of Options Nonvested Number</link:label>
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    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardRestrictedStockExerciseOfOptionsNonvestedNumber_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardRestrictedStockExerciseOfOptionsNonvestedNumber" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardRestrictedStockExerciseOfOptionsNonvestedNumber_2">Shares of unvested restricted stock remaining from the early exercise of stock options</link:label>
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    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardRestrictedStockExerciseOfOptionsNonvestedNumber_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardRestrictedStockExerciseOfOptionsNonvestedNumber" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardRestrictedStockExerciseOfOptionsNonvestedNumber_3">The number of non-vested restricted stock issued as a result of the option exercised, that validly exist and are outstanding as of the balance sheet date.</link:label>
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    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_ShareBasedCompensationArrangementByShareBasedPaymentAwardWeightedAverageRemainingContractualTermAbstract" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardWeightedAverageRemainingContractualTermAbstract" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardWeightedAverageRemainingContractualTermAbstract" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardWeightedAverageRemainingContractualTermAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardWeightedAverageRemainingContractualTermAbstract" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardWeightedAverageRemainingContractualTermAbstract">Share based Compensation Arrangement by Share based Payment Award Weighted Average Remaining Contractual Term [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardWeightedAverageRemainingContractualTermAbstract" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardWeightedAverageRemainingContractualTermAbstract" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardWeightedAverageRemainingContractualTermAbstract to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardWeightedAverageRemainingContractualTermAbstract" use="optional" />
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardWeightedAverageRemainingContractualTermAbstract" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardWeightedAverageRemainingContractualTermAbstract_2" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardWeightedAverageRemainingContractualTermAbstract to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardWeightedAverageRemainingContractualTermAbstract" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_SpecialParticipationStockIssuedDuringPeriodShares" xlink:label="SpecialParticipationStockIssuedDuringPeriodShares" xlink:title="SpecialParticipationStockIssuedDuringPeriodShares" />
    <link:label xlink:type="resource" xlink:label="label_SpecialParticipationStockIssuedDuringPeriodShares" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_SpecialParticipationStockIssuedDuringPeriodShares" xml:lang="en-US" id="label_SpecialParticipationStockIssuedDuringPeriodShares">Represents the number of shares of special participation stock issued during the reporting period.</link:label>
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    <link:label xlink:type="resource" xlink:label="label_SpecialParticipationStockIssuedDuringPeriodShares_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SpecialParticipationStockIssuedDuringPeriodShares" xml:lang="en-US" id="label_SpecialParticipationStockIssuedDuringPeriodShares_2">Special Participation Stock Issued During Period Shares</link:label>
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    <link:label xlink:type="resource" xlink:label="label_SpecialParticipationStockIssuedDuringPeriodShares_3" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SpecialParticipationStockIssuedDuringPeriodShares" xml:lang="en-US" id="label_SpecialParticipationStockIssuedDuringPeriodShares_3">Issuance of special participation stock (in shares)</link:label>
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    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_SpecialParticipationStockMember" xlink:label="SpecialParticipationStockMember" xlink:title="SpecialParticipationStockMember" />
    <link:label xlink:type="resource" xlink:label="label_SpecialParticipationStockMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SpecialParticipationStockMember" xml:lang="en-US" id="label_SpecialParticipationStockMember">Special Participation Stock [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SpecialParticipationStockMember" xlink:to="label_SpecialParticipationStockMember" xlink:title="label: SpecialParticipationStockMember to label_SpecialParticipationStockMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SpecialParticipationStockMember_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SpecialParticipationStockMember" xml:lang="en-US" id="label_SpecialParticipationStockMember_2">Special Participation Preferred Shares</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SpecialParticipationStockMember" xlink:to="label_SpecialParticipationStockMember_2" xlink:title="label: SpecialParticipationStockMember to label_SpecialParticipationStockMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SpecialParticipationStockMember_3" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_SpecialParticipationStockMember" xml:lang="en-US" id="label_SpecialParticipationStockMember_3">Special participation stock</link:label>
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    <link:label xlink:type="resource" xlink:label="label_SpecialParticipationStockMember_4" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_SpecialParticipationStockMember" xml:lang="en-US" id="label_SpecialParticipationStockMember_4">Represents information pertaining to the temporary equity attributable to special participation stock, under which the entity have the right (but not an obligation) to repurchase, at the original purchase price.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SpecialParticipationStockMember" xlink:to="label_SpecialParticipationStockMember_4" xlink:title="label: SpecialParticipationStockMember to label_SpecialParticipationStockMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_StockIncentivePlan2010Member" xlink:label="StockIncentivePlan2010Member" xlink:title="StockIncentivePlan2010Member" />
    <link:label xlink:type="resource" xlink:label="label_StockIncentivePlan2010Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_StockIncentivePlan2010Member" xml:lang="en-US" id="label_StockIncentivePlan2010Member">Stock Incentive Plan 2010 [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIncentivePlan2010Member" xlink:to="label_StockIncentivePlan2010Member" xlink:title="label: StockIncentivePlan2010Member to label_StockIncentivePlan2010Member" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIncentivePlan2010Member_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_StockIncentivePlan2010Member" xml:lang="en-US" id="label_StockIncentivePlan2010Member_2">2010 Plan</link:label>
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    <link:label xlink:type="resource" xlink:label="label_StockIncentivePlan2010Member_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_StockIncentivePlan2010Member" xml:lang="en-US" id="label_StockIncentivePlan2010Member_3">Represents information pertaining to the 2010 Stock Incentive Plan.</link:label>
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    <link:label xlink:type="resource" xlink:label="label_StockIncentivePlan2010Member_4" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_StockIncentivePlan2010Member" xml:lang="en-US" id="label_StockIncentivePlan2010Member_4">2010 Plan</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIncentivePlan2010Member" xlink:to="label_StockIncentivePlan2010Member_4" xlink:title="label: StockIncentivePlan2010Member to label_StockIncentivePlan2010Member" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_StockIncentivePlan2013Member" xlink:label="StockIncentivePlan2013Member" xlink:title="StockIncentivePlan2013Member" />
    <link:label xlink:type="resource" xlink:label="label_StockIncentivePlan2013Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_StockIncentivePlan2013Member" xml:lang="en-US" id="label_StockIncentivePlan2013Member">Stock Incentive Plan 2013 [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIncentivePlan2013Member" xlink:to="label_StockIncentivePlan2013Member" xlink:title="label: StockIncentivePlan2013Member to label_StockIncentivePlan2013Member" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIncentivePlan2013Member_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_StockIncentivePlan2013Member" xml:lang="en-US" id="label_StockIncentivePlan2013Member_2">2013 Plan</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIncentivePlan2013Member" xlink:to="label_StockIncentivePlan2013Member_2" xlink:title="label: StockIncentivePlan2013Member to label_StockIncentivePlan2013Member" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIncentivePlan2013Member_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_StockIncentivePlan2013Member" xml:lang="en-US" id="label_StockIncentivePlan2013Member_3">Represents information pertaining to the 2013 Stock Incentive Plan.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIncentivePlan2013Member" xlink:to="label_StockIncentivePlan2013Member_3" xlink:title="label: StockIncentivePlan2013Member to label_StockIncentivePlan2013Member" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_StockIssuanceCosts" xlink:label="StockIssuanceCosts" xlink:title="StockIssuanceCosts" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuanceCosts" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_StockIssuanceCosts" xml:lang="en-US" id="label_StockIssuanceCosts">Represents the aggregate cost incurred directly with the issuance of an equity security.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuanceCosts" xlink:to="label_StockIssuanceCosts" xlink:title="label: StockIssuanceCosts to label_StockIssuanceCosts" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuanceCosts_2" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_StockIssuanceCosts" xml:lang="en-US" id="label_StockIssuanceCosts_2">Issuance of stock, issuance costs</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuanceCosts" xlink:to="label_StockIssuanceCosts_2" xlink:title="label: StockIssuanceCosts to label_StockIssuanceCosts" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuanceCosts_3" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_StockIssuanceCosts" xml:lang="en-US" id="label_StockIssuanceCosts_3">Stock Issuance Costs</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuanceCosts" xlink:to="label_StockIssuanceCosts_3" xlink:title="label: StockIssuanceCosts to label_StockIssuanceCosts" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuanceCosts_4" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_StockIssuanceCosts" xml:lang="en-US" id="label_StockIssuanceCosts_4">Issuance of convertible preferred stock, issuance costs</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuanceCosts" xlink:to="label_StockIssuanceCosts_4" xlink:title="label: StockIssuanceCosts to label_StockIssuanceCosts" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_StockIssuedDuringPeriodSharesConversionOfConvertiblePreferredSecurities" xlink:label="StockIssuedDuringPeriodSharesConversionOfConvertiblePreferredSecurities" xlink:title="StockIssuedDuringPeriodSharesConversionOfConvertiblePreferredSecurities" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodSharesConversionOfConvertiblePreferredSecurities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_StockIssuedDuringPeriodSharesConversionOfConvertiblePreferredSecurities" xml:lang="en-US" id="label_StockIssuedDuringPeriodSharesConversionOfConvertiblePreferredSecurities">Stock Issued During Period Shares Conversion of Convertible Preferred Securities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodSharesConversionOfConvertiblePreferredSecurities" xlink:to="label_StockIssuedDuringPeriodSharesConversionOfConvertiblePreferredSecurities" xlink:title="label: StockIssuedDuringPeriodSharesConversionOfConvertiblePreferredSecurities to label_StockIssuedDuringPeriodSharesConversionOfConvertiblePreferredSecurities" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodSharesConversionOfConvertiblePreferredSecurities_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_StockIssuedDuringPeriodSharesConversionOfConvertiblePreferredSecurities" xml:lang="en-US" id="label_StockIssuedDuringPeriodSharesConversionOfConvertiblePreferredSecurities_2">Conversion of convertible preferred stock into common stock (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodSharesConversionOfConvertiblePreferredSecurities" xlink:to="label_StockIssuedDuringPeriodSharesConversionOfConvertiblePreferredSecurities_2" xlink:title="label: StockIssuedDuringPeriodSharesConversionOfConvertiblePreferredSecurities to label_StockIssuedDuringPeriodSharesConversionOfConvertiblePreferredSecurities" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodSharesConversionOfConvertiblePreferredSecurities_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_StockIssuedDuringPeriodSharesConversionOfConvertiblePreferredSecurities" xml:lang="en-US" id="label_StockIssuedDuringPeriodSharesConversionOfConvertiblePreferredSecurities_3">Represents the number of shares issued during the period upon the conversion of convertible preferred securities.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodSharesConversionOfConvertiblePreferredSecurities" xlink:to="label_StockIssuedDuringPeriodSharesConversionOfConvertiblePreferredSecurities_3" xlink:title="label: StockIssuedDuringPeriodSharesConversionOfConvertiblePreferredSecurities to label_StockIssuedDuringPeriodSharesConversionOfConvertiblePreferredSecurities" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock" xlink:label="StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock" xlink:title="StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock" xml:lang="en-US" id="label_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock">Stock Issued During Period Shares Conversion of Special Participation Stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock" xlink:to="label_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock" xlink:title="label: StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock to label_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock" xml:lang="en-US" id="label_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock_2">Settlement of Special Participation Preferred Shares (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock" xlink:to="label_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock_2" xlink:title="label: StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock to label_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock" xml:lang="en-US" id="label_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock_3">Represents the number of shares issued during the period upon the conversion of special participation stock.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock" xlink:to="label_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock_3" xlink:title="label: StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock to label_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock_4" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock" xml:lang="en-US" id="label_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock_4">Number of shares of common stock issued in settlement of outstanding shares of Special Participation Stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock" xlink:to="label_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock_4" xlink:title="label: StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock to label_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock_5" xlink:role="http://www.xbrl.org/2003/role/positiveLabel" xlink:title="label_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock" xml:lang="en-US" id="label_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock_5">Settlement of special participation preferred shares (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock" xlink:to="label_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock_5" xlink:title="label: StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock to label_StockIssuedDuringPeriodSharesConversionOfSpecialParticipationStock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_StockIssuedDuringPeriodSharesNewIssuesToBeMadeUponUnderwritersExerciseOfOption" xlink:label="StockIssuedDuringPeriodSharesNewIssuesToBeMadeUponUnderwritersExerciseOfOption" xlink:title="StockIssuedDuringPeriodSharesNewIssuesToBeMadeUponUnderwritersExerciseOfOption" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodSharesNewIssuesToBeMadeUponUnderwritersExerciseOfOption" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_StockIssuedDuringPeriodSharesNewIssuesToBeMadeUponUnderwritersExerciseOfOption" xml:lang="en-US" id="label_StockIssuedDuringPeriodSharesNewIssuesToBeMadeUponUnderwritersExerciseOfOption">Stock Issued During Period Shares New Issues to be Made Upon Underwriters Exercise of Option</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodSharesNewIssuesToBeMadeUponUnderwritersExerciseOfOption" xlink:to="label_StockIssuedDuringPeriodSharesNewIssuesToBeMadeUponUnderwritersExerciseOfOption" xlink:title="label: StockIssuedDuringPeriodSharesNewIssuesToBeMadeUponUnderwritersExerciseOfOption to label_StockIssuedDuringPeriodSharesNewIssuesToBeMadeUponUnderwritersExerciseOfOption" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodSharesNewIssuesToBeMadeUponUnderwritersExerciseOfOption_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_StockIssuedDuringPeriodSharesNewIssuesToBeMadeUponUnderwritersExerciseOfOption" xml:lang="en-US" id="label_StockIssuedDuringPeriodSharesNewIssuesToBeMadeUponUnderwritersExerciseOfOption_2">Number of shares issued upon the exercise of option by underwriters</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodSharesNewIssuesToBeMadeUponUnderwritersExerciseOfOption" xlink:to="label_StockIssuedDuringPeriodSharesNewIssuesToBeMadeUponUnderwritersExerciseOfOption_2" xlink:title="label: StockIssuedDuringPeriodSharesNewIssuesToBeMadeUponUnderwritersExerciseOfOption to label_StockIssuedDuringPeriodSharesNewIssuesToBeMadeUponUnderwritersExerciseOfOption" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodSharesNewIssuesToBeMadeUponUnderwritersExerciseOfOption_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_StockIssuedDuringPeriodSharesNewIssuesToBeMadeUponUnderwritersExerciseOfOption" xml:lang="en-US" id="label_StockIssuedDuringPeriodSharesNewIssuesToBeMadeUponUnderwritersExerciseOfOption_3">Represents the number of shares of common stock to be issued upon the exercise of option by underwriters.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodSharesNewIssuesToBeMadeUponUnderwritersExerciseOfOption" xlink:to="label_StockIssuedDuringPeriodSharesNewIssuesToBeMadeUponUnderwritersExerciseOfOption_3" xlink:title="label: StockIssuedDuringPeriodSharesNewIssuesToBeMadeUponUnderwritersExerciseOfOption to label_StockIssuedDuringPeriodSharesNewIssuesToBeMadeUponUnderwritersExerciseOfOption" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AreaOfRealEstateProperty" xlink:label="AreaOfRealEstateProperty" xlink:title="AreaOfRealEstateProperty" />
    <link:label xlink:type="resource" xlink:label="label_AreaOfRealEstateProperty" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_AreaOfRealEstateProperty" xml:lang="en-US" id="label_AreaOfRealEstateProperty">Office and laboratory space leased (in square feet)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AreaOfRealEstateProperty" xlink:to="label_AreaOfRealEstateProperty" xlink:title="label: AreaOfRealEstateProperty to label_AreaOfRealEstateProperty" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_AreaOfRealEstateProperty_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AreaOfRealEstateProperty" xml:lang="en-US" id="label_AreaOfRealEstateProperty_2">Area of Real Estate Property</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AreaOfRealEstateProperty" xlink:to="label_AreaOfRealEstateProperty_2" xlink:title="label: AreaOfRealEstateProperty to label_AreaOfRealEstateProperty" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_StockIssuedDuringPeriodSharesPreferredStockSubscription" xlink:label="StockIssuedDuringPeriodSharesPreferredStockSubscription" xlink:title="StockIssuedDuringPeriodSharesPreferredStockSubscription" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodSharesPreferredStockSubscription" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_StockIssuedDuringPeriodSharesPreferredStockSubscription" xml:lang="en-US" id="label_StockIssuedDuringPeriodSharesPreferredStockSubscription">Represents the number of shares issued related to the preferred stock subscription during the reporting period.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodSharesPreferredStockSubscription" xlink:to="label_StockIssuedDuringPeriodSharesPreferredStockSubscription" xlink:title="label: StockIssuedDuringPeriodSharesPreferredStockSubscription to label_StockIssuedDuringPeriodSharesPreferredStockSubscription" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodSharesPreferredStockSubscription_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_StockIssuedDuringPeriodSharesPreferredStockSubscription" xml:lang="en-US" id="label_StockIssuedDuringPeriodSharesPreferredStockSubscription_2">Stock Issued During Period Shares Preferred Stock Subscription</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodSharesPreferredStockSubscription" xlink:to="label_StockIssuedDuringPeriodSharesPreferredStockSubscription_2" xlink:title="label: StockIssuedDuringPeriodSharesPreferredStockSubscription to label_StockIssuedDuringPeriodSharesPreferredStockSubscription" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodSharesPreferredStockSubscription_3" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_StockIssuedDuringPeriodSharesPreferredStockSubscription" xml:lang="en-US" id="label_StockIssuedDuringPeriodSharesPreferredStockSubscription_3">Issuance of shares related to preferred stock subscription (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodSharesPreferredStockSubscription" xlink:to="label_StockIssuedDuringPeriodSharesPreferredStockSubscription_3" xlink:title="label: StockIssuedDuringPeriodSharesPreferredStockSubscription to label_StockIssuedDuringPeriodSharesPreferredStockSubscription" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_StockIssuedDuringPeriodValueConversionOfConvertiblePreferredSecurities" xlink:label="StockIssuedDuringPeriodValueConversionOfConvertiblePreferredSecurities" xlink:title="StockIssuedDuringPeriodValueConversionOfConvertiblePreferredSecurities" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodValueConversionOfConvertiblePreferredSecurities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_StockIssuedDuringPeriodValueConversionOfConvertiblePreferredSecurities" xml:lang="en-US" id="label_StockIssuedDuringPeriodValueConversionOfConvertiblePreferredSecurities">Stock Issued During Period Value Conversion of Convertible Preferred Securities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodValueConversionOfConvertiblePreferredSecurities" xlink:to="label_StockIssuedDuringPeriodValueConversionOfConvertiblePreferredSecurities" xlink:title="label: StockIssuedDuringPeriodValueConversionOfConvertiblePreferredSecurities to label_StockIssuedDuringPeriodValueConversionOfConvertiblePreferredSecurities" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodValueConversionOfConvertiblePreferredSecurities_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_StockIssuedDuringPeriodValueConversionOfConvertiblePreferredSecurities" xml:lang="en-US" id="label_StockIssuedDuringPeriodValueConversionOfConvertiblePreferredSecurities_2">Conversion of convertible preferred stock into common stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodValueConversionOfConvertiblePreferredSecurities" xlink:to="label_StockIssuedDuringPeriodValueConversionOfConvertiblePreferredSecurities_2" xlink:title="label: StockIssuedDuringPeriodValueConversionOfConvertiblePreferredSecurities to label_StockIssuedDuringPeriodValueConversionOfConvertiblePreferredSecurities" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodValueConversionOfConvertiblePreferredSecurities_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_StockIssuedDuringPeriodValueConversionOfConvertiblePreferredSecurities" xml:lang="en-US" id="label_StockIssuedDuringPeriodValueConversionOfConvertiblePreferredSecurities_3">Represents the value of stock issued during the period upon the conversion of convertible preferred securities.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodValueConversionOfConvertiblePreferredSecurities" xlink:to="label_StockIssuedDuringPeriodValueConversionOfConvertiblePreferredSecurities_3" xlink:title="label: StockIssuedDuringPeriodValueConversionOfConvertiblePreferredSecurities to label_StockIssuedDuringPeriodValueConversionOfConvertiblePreferredSecurities" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_StockIssuedDuringPeriodValuePreferredStockSubscription" xlink:label="StockIssuedDuringPeriodValuePreferredStockSubscription" xlink:title="StockIssuedDuringPeriodValuePreferredStockSubscription" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodValuePreferredStockSubscription" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_StockIssuedDuringPeriodValuePreferredStockSubscription" xml:lang="en-US" id="label_StockIssuedDuringPeriodValuePreferredStockSubscription">Stock Issued During Period Value Preferred Stock Subscription</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodValuePreferredStockSubscription" xlink:to="label_StockIssuedDuringPeriodValuePreferredStockSubscription" xlink:title="label: StockIssuedDuringPeriodValuePreferredStockSubscription to label_StockIssuedDuringPeriodValuePreferredStockSubscription" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodValuePreferredStockSubscription_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_StockIssuedDuringPeriodValuePreferredStockSubscription" xml:lang="en-US" id="label_StockIssuedDuringPeriodValuePreferredStockSubscription_2">Issuance of shares related to preferred stock subscription</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodValuePreferredStockSubscription" xlink:to="label_StockIssuedDuringPeriodValuePreferredStockSubscription_2" xlink:title="label: StockIssuedDuringPeriodValuePreferredStockSubscription to label_StockIssuedDuringPeriodValuePreferredStockSubscription" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodValuePreferredStockSubscription_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_StockIssuedDuringPeriodValuePreferredStockSubscription" xml:lang="en-US" id="label_StockIssuedDuringPeriodValuePreferredStockSubscription_3">Represents the value of stock issued related to preferred stock subscription during the reporting period.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodValuePreferredStockSubscription" xlink:to="label_StockIssuedDuringPeriodValuePreferredStockSubscription_3" xlink:title="label: StockIssuedDuringPeriodValuePreferredStockSubscription to label_StockIssuedDuringPeriodValuePreferredStockSubscription" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_TemporaryEquitySubscriptions" xlink:label="TemporaryEquitySubscriptions" xlink:title="TemporaryEquitySubscriptions" />
    <link:label xlink:type="resource" xlink:label="label_TemporaryEquitySubscriptions" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_TemporaryEquitySubscriptions" xml:lang="en-US" id="label_TemporaryEquitySubscriptions">Preferred stock subscription</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TemporaryEquitySubscriptions" xlink:to="label_TemporaryEquitySubscriptions" xlink:title="label: TemporaryEquitySubscriptions to label_TemporaryEquitySubscriptions" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_TemporaryEquitySubscriptions_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_TemporaryEquitySubscriptions" xml:lang="en-US" id="label_TemporaryEquitySubscriptions_2">Temporary Equity Subscriptions</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TemporaryEquitySubscriptions" xlink:to="label_TemporaryEquitySubscriptions_2" xlink:title="label: TemporaryEquitySubscriptions to label_TemporaryEquitySubscriptions" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_TemporaryEquitySubscriptions_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_TemporaryEquitySubscriptions" xml:lang="en-US" id="label_TemporaryEquitySubscriptions_3">Represents the amount of securities classified as temporary equity that have been allocated to investors to buy. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TemporaryEquitySubscriptions" xlink:to="label_TemporaryEquitySubscriptions_3" xlink:title="label: TemporaryEquitySubscriptions to label_TemporaryEquitySubscriptions" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_VestingPeriodOneMember" xlink:label="VestingPeriodOneMember" xlink:title="VestingPeriodOneMember" />
    <link:label xlink:type="resource" xlink:label="label_VestingPeriodOneMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_VestingPeriodOneMember" xml:lang="en-US" id="label_VestingPeriodOneMember">Vesting Period One [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="VestingPeriodOneMember" xlink:to="label_VestingPeriodOneMember" xlink:title="label: VestingPeriodOneMember to label_VestingPeriodOneMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_VestingPeriodOneMember_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_VestingPeriodOneMember" xml:lang="en-US" id="label_VestingPeriodOneMember_2">Percent vesting one calendar year from vesting start date</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="VestingPeriodOneMember" xlink:to="label_VestingPeriodOneMember_2" xlink:title="label: VestingPeriodOneMember to label_VestingPeriodOneMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_VestingPeriodOneMember_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_VestingPeriodOneMember" xml:lang="en-US" id="label_VestingPeriodOneMember_3">Represents the first vesting period of options.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="VestingPeriodOneMember" xlink:to="label_VestingPeriodOneMember_3" xlink:title="label: VestingPeriodOneMember to label_VestingPeriodOneMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_VestingPeriodTwoMember" xlink:label="VestingPeriodTwoMember" xlink:title="VestingPeriodTwoMember" />
    <link:label xlink:type="resource" xlink:label="label_VestingPeriodTwoMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_VestingPeriodTwoMember" xml:lang="en-US" id="label_VestingPeriodTwoMember">Vesting Period Two [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="VestingPeriodTwoMember" xlink:to="label_VestingPeriodTwoMember" xlink:title="label: VestingPeriodTwoMember to label_VestingPeriodTwoMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_VestingPeriodTwoMember_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_VestingPeriodTwoMember" xml:lang="en-US" id="label_VestingPeriodTwoMember_2">Percentage vesting on the first day of each month after one calendar year</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="VestingPeriodTwoMember" xlink:to="label_VestingPeriodTwoMember_2" xlink:title="label: VestingPeriodTwoMember to label_VestingPeriodTwoMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_VestingPeriodTwoMember_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_VestingPeriodTwoMember" xml:lang="en-US" id="label_VestingPeriodTwoMember_3">Represents the second vesting period of options.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="VestingPeriodTwoMember" xlink:to="label_VestingPeriodTwoMember_3" xlink:title="label: VestingPeriodTwoMember to label_VestingPeriodTwoMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_CurrentFiscalYearEndDate" xlink:label="CurrentFiscalYearEndDate" xlink:title="CurrentFiscalYearEndDate" />
    <link:label xlink:type="resource" xlink:label="label_CurrentFiscalYearEndDate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_CurrentFiscalYearEndDate" xml:lang="en-US" id="label_CurrentFiscalYearEndDate">Current Fiscal Year End Date</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="CurrentFiscalYearEndDate" xlink:to="label_CurrentFiscalYearEndDate" xlink:title="label: CurrentFiscalYearEndDate to label_CurrentFiscalYearEndDate" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="AwardTypeAxis" xlink:title="AwardTypeAxis" />
    <link:label xlink:type="resource" xlink:label="label_AwardTypeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AwardTypeAxis" xml:lang="en-US" id="label_AwardTypeAxis">Award Type [Axis]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AwardTypeAxis" xlink:to="label_AwardTypeAxis" xlink:title="label: AwardTypeAxis to label_AwardTypeAxis" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_WhollyOwnedSubsidiaryParentOwnershipInterestTable" xlink:label="WhollyOwnedSubsidiaryParentOwnershipInterestTable" xlink:title="WhollyOwnedSubsidiaryParentOwnershipInterestTable" />
    <link:label xlink:type="resource" xlink:label="label_WhollyOwnedSubsidiaryParentOwnershipInterestTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_WhollyOwnedSubsidiaryParentOwnershipInterestTable" xml:lang="en-US" id="label_WhollyOwnedSubsidiaryParentOwnershipInterestTable">Wholly Owned Subsidiary Parent Ownership Interest [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="WhollyOwnedSubsidiaryParentOwnershipInterestTable" xlink:to="label_WhollyOwnedSubsidiaryParentOwnershipInterestTable" xlink:title="label: WhollyOwnedSubsidiaryParentOwnershipInterestTable to label_WhollyOwnedSubsidiaryParentOwnershipInterestTable" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_WhollyOwnedSubsidiaryParentOwnershipInterestLineItems" xlink:label="WhollyOwnedSubsidiaryParentOwnershipInterestLineItems" xlink:title="WhollyOwnedSubsidiaryParentOwnershipInterestLineItems" />
    <link:label xlink:type="resource" xlink:label="label_WhollyOwnedSubsidiaryParentOwnershipInterestLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_WhollyOwnedSubsidiaryParentOwnershipInterestLineItems" xml:lang="en-US" id="label_WhollyOwnedSubsidiaryParentOwnershipInterestLineItems">Wholly Owned Subsidiary Parent Ownership Interest [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="WhollyOwnedSubsidiaryParentOwnershipInterestLineItems" xlink:to="label_WhollyOwnedSubsidiaryParentOwnershipInterestLineItems" xlink:title="label: WhollyOwnedSubsidiaryParentOwnershipInterestLineItems to label_WhollyOwnedSubsidiaryParentOwnershipInterestLineItems" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_WhollyOwnedSubsidiaryParentOwnershipInterestLineItems_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_WhollyOwnedSubsidiaryParentOwnershipInterestLineItems" xml:lang="en-US" id="label_WhollyOwnedSubsidiaryParentOwnershipInterestLineItems_2">Basis of Presentation</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="WhollyOwnedSubsidiaryParentOwnershipInterestLineItems" xlink:to="label_WhollyOwnedSubsidiaryParentOwnershipInterestLineItems_2" xlink:title="label: WhollyOwnedSubsidiaryParentOwnershipInterestLineItems to label_WhollyOwnedSubsidiaryParentOwnershipInterestLineItems" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_WhollyOwnedSubsidiaryParentOwnershipInterestLineItems_3" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_WhollyOwnedSubsidiaryParentOwnershipInterestLineItems" xml:lang="en-US" id="label_WhollyOwnedSubsidiaryParentOwnershipInterestLineItems_3">Principles of Consolidation</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="WhollyOwnedSubsidiaryParentOwnershipInterestLineItems" xlink:to="label_WhollyOwnedSubsidiaryParentOwnershipInterestLineItems_3" xlink:title="label: WhollyOwnedSubsidiaryParentOwnershipInterestLineItems to label_WhollyOwnedSubsidiaryParentOwnershipInterestLineItems" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_ConcentrationsOfCreditRiskAndOffBalanceSheetRiskPolicyTextBlock" xlink:label="ConcentrationsOfCreditRiskAndOffBalanceSheetRiskPolicyTextBlock" xlink:title="ConcentrationsOfCreditRiskAndOffBalanceSheetRiskPolicyTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_ConcentrationsOfCreditRiskAndOffBalanceSheetRiskPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ConcentrationsOfCreditRiskAndOffBalanceSheetRiskPolicyTextBlock" xml:lang="en-US" id="label_ConcentrationsOfCreditRiskAndOffBalanceSheetRiskPolicyTextBlock">Concentrations of Credit Risk and Off Balance Sheet Risk [Policy Text Block]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ConcentrationsOfCreditRiskAndOffBalanceSheetRiskPolicyTextBlock" xlink:to="label_ConcentrationsOfCreditRiskAndOffBalanceSheetRiskPolicyTextBlock" xlink:title="label: ConcentrationsOfCreditRiskAndOffBalanceSheetRiskPolicyTextBlock to label_ConcentrationsOfCreditRiskAndOffBalanceSheetRiskPolicyTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ConcentrationsOfCreditRiskAndOffBalanceSheetRiskPolicyTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ConcentrationsOfCreditRiskAndOffBalanceSheetRiskPolicyTextBlock" xml:lang="en-US" id="label_ConcentrationsOfCreditRiskAndOffBalanceSheetRiskPolicyTextBlock_2">Concentrations of Credit Risk and Off-Balance Sheet Risk</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ConcentrationsOfCreditRiskAndOffBalanceSheetRiskPolicyTextBlock" xlink:to="label_ConcentrationsOfCreditRiskAndOffBalanceSheetRiskPolicyTextBlock_2" xlink:title="label: ConcentrationsOfCreditRiskAndOffBalanceSheetRiskPolicyTextBlock to label_ConcentrationsOfCreditRiskAndOffBalanceSheetRiskPolicyTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ConcentrationsOfCreditRiskAndOffBalanceSheetRiskPolicyTextBlock_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_ConcentrationsOfCreditRiskAndOffBalanceSheetRiskPolicyTextBlock" xml:lang="en-US" id="label_ConcentrationsOfCreditRiskAndOffBalanceSheetRiskPolicyTextBlock_3">Disclosure of accounting policy for concentrations of credit risk and off-balance sheet risk.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ConcentrationsOfCreditRiskAndOffBalanceSheetRiskPolicyTextBlock" xlink:to="label_ConcentrationsOfCreditRiskAndOffBalanceSheetRiskPolicyTextBlock_3" xlink:title="label: ConcentrationsOfCreditRiskAndOffBalanceSheetRiskPolicyTextBlock to label_ConcentrationsOfCreditRiskAndOffBalanceSheetRiskPolicyTextBlock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_OrganizationalCostsPolicyTextBlock" xlink:label="OrganizationalCostsPolicyTextBlock" xlink:title="OrganizationalCostsPolicyTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_OrganizationalCostsPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_OrganizationalCostsPolicyTextBlock" xml:lang="en-US" id="label_OrganizationalCostsPolicyTextBlock">Organizational Costs [Policy Text Block]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OrganizationalCostsPolicyTextBlock" xlink:to="label_OrganizationalCostsPolicyTextBlock" xlink:title="label: OrganizationalCostsPolicyTextBlock to label_OrganizationalCostsPolicyTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OrganizationalCostsPolicyTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_OrganizationalCostsPolicyTextBlock" xml:lang="en-US" id="label_OrganizationalCostsPolicyTextBlock_2">Organizational Costs</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OrganizationalCostsPolicyTextBlock" xlink:to="label_OrganizationalCostsPolicyTextBlock_2" xlink:title="label: OrganizationalCostsPolicyTextBlock to label_OrganizationalCostsPolicyTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OrganizationalCostsPolicyTextBlock_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_OrganizationalCostsPolicyTextBlock" xml:lang="en-US" id="label_OrganizationalCostsPolicyTextBlock_3">Disclosure of accounting policy for organizational costs.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OrganizationalCostsPolicyTextBlock" xlink:to="label_OrganizationalCostsPolicyTextBlock_3" xlink:title="label: OrganizationalCostsPolicyTextBlock to label_OrganizationalCostsPolicyTextBlock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_NPMPharmaIncMember" xlink:label="NPMPharmaIncMember" xlink:title="NPMPharmaIncMember" />
    <link:label xlink:type="resource" xlink:label="label_NPMPharmaIncMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_NPMPharmaIncMember" xml:lang="en-US" id="label_NPMPharmaIncMember">NPM Pharma Inc [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="NPMPharmaIncMember" xlink:to="label_NPMPharmaIncMember" xlink:title="label: NPMPharmaIncMember to label_NPMPharmaIncMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_NPMPharmaIncMember_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_NPMPharmaIncMember" xml:lang="en-US" id="label_NPMPharmaIncMember_2">NPM</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="NPMPharmaIncMember" xlink:to="label_NPMPharmaIncMember_2" xlink:title="label: NPMPharmaIncMember to label_NPMPharmaIncMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_NPMPharmaIncMember_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_NPMPharmaIncMember" xml:lang="en-US" id="label_NPMPharmaIncMember_3">Represents information pertaining to NPM Pharma Inc. (NPM, a Canadian corporation).</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="NPMPharmaIncMember" xlink:to="label_NPMPharmaIncMember_3" xlink:title="label: NPMPharmaIncMember to label_NPMPharmaIncMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock" xlink:label="ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock" xlink:title="ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock" xml:lang="en-US" id="label_ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock">Schedule of estimated useful lives of real estate assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock" xlink:to="label_ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock" xlink:title="label: ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock to label_ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock" xml:lang="en-US" id="label_ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock_2">Schedule of Property Plant and Equipment Useful Life [Table Text Block]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock" xlink:to="label_ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock_2" xlink:title="label: ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock to label_ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock" xml:lang="en-US" id="label_ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock_3">Tabular disclosure of the useful life of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock" xlink:to="label_ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock_3" xlink:title="label: ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock to label_ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_NumberOfWhollyOwnedSubsidiariesRequiringConsolidation" xlink:label="NumberOfWhollyOwnedSubsidiariesRequiringConsolidation" xlink:title="NumberOfWhollyOwnedSubsidiariesRequiringConsolidation" />
    <link:label xlink:type="resource" xlink:label="label_NumberOfWhollyOwnedSubsidiariesRequiringConsolidation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_NumberOfWhollyOwnedSubsidiariesRequiringConsolidation" xml:lang="en-US" id="label_NumberOfWhollyOwnedSubsidiariesRequiringConsolidation">Number of Wholly Owned Subsidiaries Requiring Consolidation</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="NumberOfWhollyOwnedSubsidiariesRequiringConsolidation" xlink:to="label_NumberOfWhollyOwnedSubsidiariesRequiringConsolidation" xlink:title="label: NumberOfWhollyOwnedSubsidiariesRequiringConsolidation to label_NumberOfWhollyOwnedSubsidiariesRequiringConsolidation" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_NumberOfWhollyOwnedSubsidiariesRequiringConsolidation_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_NumberOfWhollyOwnedSubsidiariesRequiringConsolidation" xml:lang="en-US" id="label_NumberOfWhollyOwnedSubsidiariesRequiringConsolidation_2">Number of wholly-owned subsidiaries requiring consolidation</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="NumberOfWhollyOwnedSubsidiariesRequiringConsolidation" xlink:to="label_NumberOfWhollyOwnedSubsidiariesRequiringConsolidation_2" xlink:title="label: NumberOfWhollyOwnedSubsidiariesRequiringConsolidation to label_NumberOfWhollyOwnedSubsidiariesRequiringConsolidation" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_NumberOfWhollyOwnedSubsidiariesRequiringConsolidation_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_NumberOfWhollyOwnedSubsidiariesRequiringConsolidation" xml:lang="en-US" id="label_NumberOfWhollyOwnedSubsidiariesRequiringConsolidation_3">Represents the number of wholly-owned subsidiaries requiring consolidation.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="NumberOfWhollyOwnedSubsidiariesRequiringConsolidation" xlink:to="label_NumberOfWhollyOwnedSubsidiariesRequiringConsolidation_3" xlink:title="label: NumberOfWhollyOwnedSubsidiariesRequiringConsolidation to label_NumberOfWhollyOwnedSubsidiariesRequiringConsolidation" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_ResearchAgreement2013Member" xlink:label="ResearchAgreement2013Member" xlink:title="ResearchAgreement2013Member" />
    <link:label xlink:type="resource" xlink:label="label_ResearchAgreement2013Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ResearchAgreement2013Member" xml:lang="en-US" id="label_ResearchAgreement2013Member">Research Agreement 2013 [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ResearchAgreement2013Member" xlink:to="label_ResearchAgreement2013Member" xlink:title="label: ResearchAgreement2013Member to label_ResearchAgreement2013Member" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ResearchAgreement2013Member_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ResearchAgreement2013Member" xml:lang="en-US" id="label_ResearchAgreement2013Member_2">Research agreement executed during 2013</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ResearchAgreement2013Member" xlink:to="label_ResearchAgreement2013Member_2" xlink:title="label: ResearchAgreement2013Member to label_ResearchAgreement2013Member" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ResearchAgreement2013Member_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_ResearchAgreement2013Member" xml:lang="en-US" id="label_ResearchAgreement2013Member_3">Represents information pertaining to research agreement executed during 2013.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ResearchAgreement2013Member" xlink:to="label_ResearchAgreement2013Member_3" xlink:title="label: ResearchAgreement2013Member to label_ResearchAgreement2013Member" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_ResearchAgreement2011Member" xlink:label="ResearchAgreement2011Member" xlink:title="ResearchAgreement2011Member" />
    <link:label xlink:type="resource" xlink:label="label_ResearchAgreement2011Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ResearchAgreement2011Member" xml:lang="en-US" id="label_ResearchAgreement2011Member">Research Agreement 2011 [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ResearchAgreement2011Member" xlink:to="label_ResearchAgreement2011Member" xlink:title="label: ResearchAgreement2011Member to label_ResearchAgreement2011Member" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ResearchAgreement2011Member_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ResearchAgreement2011Member" xml:lang="en-US" id="label_ResearchAgreement2011Member_2">Research agreement executed during 2011</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ResearchAgreement2011Member" xlink:to="label_ResearchAgreement2011Member_2" xlink:title="label: ResearchAgreement2011Member to label_ResearchAgreement2011Member" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ResearchAgreement2011Member_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_ResearchAgreement2011Member" xml:lang="en-US" id="label_ResearchAgreement2011Member_3">Represents information pertaining to research agreement executed during 2011.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ResearchAgreement2011Member" xlink:to="label_ResearchAgreement2011Member_3" xlink:title="label: ResearchAgreement2011Member to label_ResearchAgreement2011Member" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_RevenueRecognitionMilestoneMethodNumberOfResearchAgreements" xlink:label="RevenueRecognitionMilestoneMethodNumberOfResearchAgreements" xlink:title="RevenueRecognitionMilestoneMethodNumberOfResearchAgreements" />
    <link:label xlink:type="resource" xlink:label="label_RevenueRecognitionMilestoneMethodNumberOfResearchAgreements" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_RevenueRecognitionMilestoneMethodNumberOfResearchAgreements" xml:lang="en-US" id="label_RevenueRecognitionMilestoneMethodNumberOfResearchAgreements">Revenue Recognition Milestone Method Number of Research Agreements</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="RevenueRecognitionMilestoneMethodNumberOfResearchAgreements" xlink:to="label_RevenueRecognitionMilestoneMethodNumberOfResearchAgreements" xlink:title="label: RevenueRecognitionMilestoneMethodNumberOfResearchAgreements to label_RevenueRecognitionMilestoneMethodNumberOfResearchAgreements" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_RevenueRecognitionMilestoneMethodNumberOfResearchAgreements_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_RevenueRecognitionMilestoneMethodNumberOfResearchAgreements" xml:lang="en-US" id="label_RevenueRecognitionMilestoneMethodNumberOfResearchAgreements_2">Number of research agreements</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="RevenueRecognitionMilestoneMethodNumberOfResearchAgreements" xlink:to="label_RevenueRecognitionMilestoneMethodNumberOfResearchAgreements_2" xlink:title="label: RevenueRecognitionMilestoneMethodNumberOfResearchAgreements to label_RevenueRecognitionMilestoneMethodNumberOfResearchAgreements" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_RevenueRecognitionMilestoneMethodNumberOfResearchAgreements_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_RevenueRecognitionMilestoneMethodNumberOfResearchAgreements" xml:lang="en-US" id="label_RevenueRecognitionMilestoneMethodNumberOfResearchAgreements_3">Represents the number of research agreements for which revenue is recognized as per milestone method of revenue recognition.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="RevenueRecognitionMilestoneMethodNumberOfResearchAgreements" xlink:to="label_RevenueRecognitionMilestoneMethodNumberOfResearchAgreements_3" xlink:title="label: RevenueRecognitionMilestoneMethodNumberOfResearchAgreements to label_RevenueRecognitionMilestoneMethodNumberOfResearchAgreements" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_UpfrontPaymentReceived" xlink:label="UpfrontPaymentReceived" xlink:title="UpfrontPaymentReceived" />
    <link:label xlink:type="resource" xlink:label="label_UpfrontPaymentReceived" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_UpfrontPaymentReceived" xml:lang="en-US" id="label_UpfrontPaymentReceived">Upfront Payment Received</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="UpfrontPaymentReceived" xlink:to="label_UpfrontPaymentReceived" xlink:title="label: UpfrontPaymentReceived to label_UpfrontPaymentReceived" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_UpfrontPaymentReceived_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_UpfrontPaymentReceived" xml:lang="en-US" id="label_UpfrontPaymentReceived_2">Upfront payment not representing substantive milestone</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="UpfrontPaymentReceived" xlink:to="label_UpfrontPaymentReceived_2" xlink:title="label: UpfrontPaymentReceived to label_UpfrontPaymentReceived" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_UpfrontPaymentReceived_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_UpfrontPaymentReceived" xml:lang="en-US" id="label_UpfrontPaymentReceived_3">Represents the amount of upfront payment received under research agreements.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="UpfrontPaymentReceived" xlink:to="label_UpfrontPaymentReceived_3" xlink:title="label: UpfrontPaymentReceived to label_UpfrontPaymentReceived" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_DocumentPeriodEndDate" xlink:label="DocumentPeriodEndDate" xlink:title="DocumentPeriodEndDate" />
    <link:label xlink:type="resource" xlink:label="label_DocumentPeriodEndDate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_DocumentPeriodEndDate" xml:lang="en-US" id="label_DocumentPeriodEndDate">Document Period End Date</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DocumentPeriodEndDate" xlink:to="label_DocumentPeriodEndDate" xlink:title="label: DocumentPeriodEndDate to label_DocumentPeriodEndDate" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_RevenueRecognitionMilestoneMethodNumberOfMilestonesMet" xlink:label="RevenueRecognitionMilestoneMethodNumberOfMilestonesMet" xlink:title="RevenueRecognitionMilestoneMethodNumberOfMilestonesMet" />
    <link:label xlink:type="resource" xlink:label="label_RevenueRecognitionMilestoneMethodNumberOfMilestonesMet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_RevenueRecognitionMilestoneMethodNumberOfMilestonesMet" xml:lang="en-US" id="label_RevenueRecognitionMilestoneMethodNumberOfMilestonesMet">Revenue Recognition Milestone Method Number of Milestones Met</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="RevenueRecognitionMilestoneMethodNumberOfMilestonesMet" xlink:to="label_RevenueRecognitionMilestoneMethodNumberOfMilestonesMet" xlink:title="label: RevenueRecognitionMilestoneMethodNumberOfMilestonesMet to label_RevenueRecognitionMilestoneMethodNumberOfMilestonesMet" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_RevenueRecognitionMilestoneMethodNumberOfMilestonesMet_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_RevenueRecognitionMilestoneMethodNumberOfMilestonesMet" xml:lang="en-US" id="label_RevenueRecognitionMilestoneMethodNumberOfMilestonesMet_2">Number of milestones met</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="RevenueRecognitionMilestoneMethodNumberOfMilestonesMet" xlink:to="label_RevenueRecognitionMilestoneMethodNumberOfMilestonesMet_2" xlink:title="label: RevenueRecognitionMilestoneMethodNumberOfMilestonesMet to label_RevenueRecognitionMilestoneMethodNumberOfMilestonesMet" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_RevenueRecognitionMilestoneMethodNumberOfMilestonesMet_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_RevenueRecognitionMilestoneMethodNumberOfMilestonesMet" xml:lang="en-US" id="label_RevenueRecognitionMilestoneMethodNumberOfMilestonesMet_3">Represents the number of milestones met for recognition of revenue as per milestone method of revenue recognition.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="RevenueRecognitionMilestoneMethodNumberOfMilestonesMet" xlink:to="label_RevenueRecognitionMilestoneMethodNumberOfMilestonesMet_3" xlink:title="label: RevenueRecognitionMilestoneMethodNumberOfMilestonesMet to label_RevenueRecognitionMilestoneMethodNumberOfMilestonesMet" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToUpfrontPayment" xlink:label="RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToUpfrontPayment" xlink:title="RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToUpfrontPayment" />
    <link:label xlink:type="resource" xlink:label="label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToUpfrontPayment" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToUpfrontPayment" xml:lang="en-US" id="label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToUpfrontPayment">Revenue Recognition Milestone Method Revenue Recognized Related to Upfront Payment</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToUpfrontPayment" xlink:to="label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToUpfrontPayment" xlink:title="label: RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToUpfrontPayment to label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToUpfrontPayment" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToUpfrontPayment_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToUpfrontPayment" xml:lang="en-US" id="label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToUpfrontPayment_2">Amount recognized related to upfront payment</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToUpfrontPayment" xlink:to="label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToUpfrontPayment_2" xlink:title="label: RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToUpfrontPayment to label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToUpfrontPayment" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToUpfrontPayment_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToUpfrontPayment" xml:lang="en-US" id="label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToUpfrontPayment_3">Represents the amount of consideration recognized during the period related to upfront payments under milestone method of revenue recognition.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToUpfrontPayment" xlink:to="label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToUpfrontPayment_3" xlink:title="label: RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToUpfrontPayment to label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToUpfrontPayment" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToOtherMilestones" xlink:label="RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToOtherMilestones" xlink:title="RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToOtherMilestones" />
    <link:label xlink:type="resource" xlink:label="label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToOtherMilestones" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToOtherMilestones" xml:lang="en-US" id="label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToOtherMilestones">Revenue Recognition Milestone Method Revenue Recognized Related to Other Milestones</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToOtherMilestones" xlink:to="label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToOtherMilestones" xlink:title="label: RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToOtherMilestones to label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToOtherMilestones" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToOtherMilestones_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToOtherMilestones" xml:lang="en-US" id="label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToOtherMilestones_2">Amount recognized related to other milestones</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToOtherMilestones" xlink:to="label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToOtherMilestones_2" xlink:title="label: RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToOtherMilestones to label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToOtherMilestones" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToOtherMilestones_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToOtherMilestones" xml:lang="en-US" id="label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToOtherMilestones_3">Represents the amount of consideration recognized during the period related to other milestones under milestone method of revenue recognition.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToOtherMilestones" xlink:to="label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToOtherMilestones_3" xlink:title="label: RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToOtherMilestones to label_RevenueRecognitionMilestoneMethodRevenueRecognizedRelatedToOtherMilestones" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_AmountOfFederalGrantAwarded" xlink:label="AmountOfFederalGrantAwarded" xlink:title="AmountOfFederalGrantAwarded" />
    <link:label xlink:type="resource" xlink:label="label_AmountOfFederalGrantAwarded" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AmountOfFederalGrantAwarded" xml:lang="en-US" id="label_AmountOfFederalGrantAwarded">Amount of Federal Grant Awarded</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AmountOfFederalGrantAwarded" xlink:to="label_AmountOfFederalGrantAwarded" xlink:title="label: AmountOfFederalGrantAwarded to label_AmountOfFederalGrantAwarded" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_AmountOfFederalGrantAwarded_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_AmountOfFederalGrantAwarded" xml:lang="en-US" id="label_AmountOfFederalGrantAwarded_2">Amount of federal grant awarded under QTDP</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AmountOfFederalGrantAwarded" xlink:to="label_AmountOfFederalGrantAwarded_2" xlink:title="label: AmountOfFederalGrantAwarded to label_AmountOfFederalGrantAwarded" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_AmountOfFederalGrantAwarded_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_AmountOfFederalGrantAwarded" xml:lang="en-US" id="label_AmountOfFederalGrantAwarded_3">Represents the amount of federal grant awarded during the period.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AmountOfFederalGrantAwarded" xlink:to="label_AmountOfFederalGrantAwarded_3" xlink:title="label: AmountOfFederalGrantAwarded to label_AmountOfFederalGrantAwarded" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_AmountOfFederalGrantReceivedAndRecognizedInIncome" xlink:label="AmountOfFederalGrantReceivedAndRecognizedInIncome" xlink:title="AmountOfFederalGrantReceivedAndRecognizedInIncome" />
    <link:label xlink:type="resource" xlink:label="label_AmountOfFederalGrantReceivedAndRecognizedInIncome" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AmountOfFederalGrantReceivedAndRecognizedInIncome" xml:lang="en-US" id="label_AmountOfFederalGrantReceivedAndRecognizedInIncome">Amount of Federal Grant Received and Recognized in Income</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AmountOfFederalGrantReceivedAndRecognizedInIncome" xlink:to="label_AmountOfFederalGrantReceivedAndRecognizedInIncome" xlink:title="label: AmountOfFederalGrantReceivedAndRecognizedInIncome to label_AmountOfFederalGrantReceivedAndRecognizedInIncome" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_AmountOfFederalGrantReceivedAndRecognizedInIncome_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_AmountOfFederalGrantReceivedAndRecognizedInIncome" xml:lang="en-US" id="label_AmountOfFederalGrantReceivedAndRecognizedInIncome_2">Amount of federal grant received and recognized in income</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AmountOfFederalGrantReceivedAndRecognizedInIncome" xlink:to="label_AmountOfFederalGrantReceivedAndRecognizedInIncome_2" xlink:title="label: AmountOfFederalGrantReceivedAndRecognizedInIncome to label_AmountOfFederalGrantReceivedAndRecognizedInIncome" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_AmountOfFederalGrantReceivedAndRecognizedInIncome_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_AmountOfFederalGrantReceivedAndRecognizedInIncome" xml:lang="en-US" id="label_AmountOfFederalGrantReceivedAndRecognizedInIncome_3">Represents the amount of federal grant received and recognized in income during the period.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AmountOfFederalGrantReceivedAndRecognizedInIncome" xlink:to="label_AmountOfFederalGrantReceivedAndRecognizedInIncome_3" xlink:title="label: AmountOfFederalGrantReceivedAndRecognizedInIncome to label_AmountOfFederalGrantReceivedAndRecognizedInIncome" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_StockIssuedDuringPeriodValuePreferredStockNetOfIssuanceCosts" xlink:label="StockIssuedDuringPeriodValuePreferredStockNetOfIssuanceCosts" xlink:title="StockIssuedDuringPeriodValuePreferredStockNetOfIssuanceCosts" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodValuePreferredStockNetOfIssuanceCosts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_StockIssuedDuringPeriodValuePreferredStockNetOfIssuanceCosts" xml:lang="en-US" id="label_StockIssuedDuringPeriodValuePreferredStockNetOfIssuanceCosts">Stock Issued During Period Value Preferred Stock Net of Issuance Costs</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodValuePreferredStockNetOfIssuanceCosts" xlink:to="label_StockIssuedDuringPeriodValuePreferredStockNetOfIssuanceCosts" xlink:title="label: StockIssuedDuringPeriodValuePreferredStockNetOfIssuanceCosts to label_StockIssuedDuringPeriodValuePreferredStockNetOfIssuanceCosts" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodValuePreferredStockNetOfIssuanceCosts_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_StockIssuedDuringPeriodValuePreferredStockNetOfIssuanceCosts" xml:lang="en-US" id="label_StockIssuedDuringPeriodValuePreferredStockNetOfIssuanceCosts_2">Issuance of convertible preferred stock, net of issuance costs</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodValuePreferredStockNetOfIssuanceCosts" xlink:to="label_StockIssuedDuringPeriodValuePreferredStockNetOfIssuanceCosts_2" xlink:title="label: StockIssuedDuringPeriodValuePreferredStockNetOfIssuanceCosts to label_StockIssuedDuringPeriodValuePreferredStockNetOfIssuanceCosts" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodValuePreferredStockNetOfIssuanceCosts_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_StockIssuedDuringPeriodValuePreferredStockNetOfIssuanceCosts" xml:lang="en-US" id="label_StockIssuedDuringPeriodValuePreferredStockNetOfIssuanceCosts_3">Represents the value of convertible preferred stock issued during the reporting period, net of issuance costs.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodValuePreferredStockNetOfIssuanceCosts" xlink:to="label_StockIssuedDuringPeriodValuePreferredStockNetOfIssuanceCosts_3" xlink:title="label: StockIssuedDuringPeriodValuePreferredStockNetOfIssuanceCosts to label_StockIssuedDuringPeriodValuePreferredStockNetOfIssuanceCosts" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_StockIssuedDuringPeriodSharesPreferredStockNetOfIssuanceCosts" xlink:label="StockIssuedDuringPeriodSharesPreferredStockNetOfIssuanceCosts" xlink:title="StockIssuedDuringPeriodSharesPreferredStockNetOfIssuanceCosts" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodSharesPreferredStockNetOfIssuanceCosts" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_StockIssuedDuringPeriodSharesPreferredStockNetOfIssuanceCosts" xml:lang="en-US" id="label_StockIssuedDuringPeriodSharesPreferredStockNetOfIssuanceCosts">Represents the number of shares of convertible preferred stock issued during the reporting period, net of issuance costs.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodSharesPreferredStockNetOfIssuanceCosts" xlink:to="label_StockIssuedDuringPeriodSharesPreferredStockNetOfIssuanceCosts" xlink:title="label: StockIssuedDuringPeriodSharesPreferredStockNetOfIssuanceCosts to label_StockIssuedDuringPeriodSharesPreferredStockNetOfIssuanceCosts" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodSharesPreferredStockNetOfIssuanceCosts_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_StockIssuedDuringPeriodSharesPreferredStockNetOfIssuanceCosts" xml:lang="en-US" id="label_StockIssuedDuringPeriodSharesPreferredStockNetOfIssuanceCosts_2">Stock Issued During Period Shares Preferred Stock Net of Issuance Costs</link:label>
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    <link:label xlink:type="resource" xlink:label="label_SeriesA2PreferredStockSubscriptionIssuedSharesNetOfIssuanceCosts_3" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SeriesA2PreferredStockSubscriptionIssuedSharesNetOfIssuanceCosts" xml:lang="en-US" id="label_SeriesA2PreferredStockSubscriptionIssuedSharesNetOfIssuanceCosts_3">Series A2 Preferred Stock Subscription Issued Shares Net of Issuance Costs</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesA2PreferredStockSubscriptionIssuedSharesNetOfIssuanceCosts" xlink:to="label_SeriesA2PreferredStockSubscriptionIssuedSharesNetOfIssuanceCosts_3" xlink:title="label: SeriesA2PreferredStockSubscriptionIssuedSharesNetOfIssuanceCosts to label_SeriesA2PreferredStockSubscriptionIssuedSharesNetOfIssuanceCosts" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_SeriesA3PreferredStockSubscriptionIssuedValue" xlink:label="SeriesA3PreferredStockSubscriptionIssuedValue" xlink:title="SeriesA3PreferredStockSubscriptionIssuedValue" />
    <link:label xlink:type="resource" xlink:label="label_SeriesA3PreferredStockSubscriptionIssuedValue" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_SeriesA3PreferredStockSubscriptionIssuedValue" xml:lang="en-US" id="label_SeriesA3PreferredStockSubscriptionIssuedValue">Represents the value of Series A-3 preferred stock subscription not issued.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesA3PreferredStockSubscriptionIssuedValue" xlink:to="label_SeriesA3PreferredStockSubscriptionIssuedValue" xlink:title="label: SeriesA3PreferredStockSubscriptionIssuedValue to label_SeriesA3PreferredStockSubscriptionIssuedValue" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesA3PreferredStockSubscriptionIssuedValue_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SeriesA3PreferredStockSubscriptionIssuedValue" xml:lang="en-US" id="label_SeriesA3PreferredStockSubscriptionIssuedValue_2">Series A3 Preferred Stock Subscription Issued Value</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesA3PreferredStockSubscriptionIssuedValue" xlink:to="label_SeriesA3PreferredStockSubscriptionIssuedValue_2" xlink:title="label: SeriesA3PreferredStockSubscriptionIssuedValue to label_SeriesA3PreferredStockSubscriptionIssuedValue" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesA3PreferredStockSubscriptionIssuedValue_3" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SeriesA3PreferredStockSubscriptionIssuedValue" xml:lang="en-US" id="label_SeriesA3PreferredStockSubscriptionIssuedValue_3">Proceeds from the sale of Series A-3 convertible preferred stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesA3PreferredStockSubscriptionIssuedValue" xlink:to="label_SeriesA3PreferredStockSubscriptionIssuedValue_3" xlink:title="label: SeriesA3PreferredStockSubscriptionIssuedValue to label_SeriesA3PreferredStockSubscriptionIssuedValue" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_SeriesA3PreferredStockSubscriptionIssuedShares" xlink:label="SeriesA3PreferredStockSubscriptionIssuedShares" xlink:title="SeriesA3PreferredStockSubscriptionIssuedShares" />
    <link:label xlink:type="resource" xlink:label="label_SeriesA3PreferredStockSubscriptionIssuedShares" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SeriesA3PreferredStockSubscriptionIssuedShares" xml:lang="en-US" id="label_SeriesA3PreferredStockSubscriptionIssuedShares">Series A3 Preferred Stock Subscription Issued Shares</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesA3PreferredStockSubscriptionIssuedShares" xlink:to="label_SeriesA3PreferredStockSubscriptionIssuedShares" xlink:title="label: SeriesA3PreferredStockSubscriptionIssuedShares to label_SeriesA3PreferredStockSubscriptionIssuedShares" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesA3PreferredStockSubscriptionIssuedShares_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SeriesA3PreferredStockSubscriptionIssuedShares" xml:lang="en-US" id="label_SeriesA3PreferredStockSubscriptionIssuedShares_2">Proceeds from the sale of Series A-3 convertible preferred stock (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesA3PreferredStockSubscriptionIssuedShares" xlink:to="label_SeriesA3PreferredStockSubscriptionIssuedShares_2" xlink:title="label: SeriesA3PreferredStockSubscriptionIssuedShares to label_SeriesA3PreferredStockSubscriptionIssuedShares" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesA3PreferredStockSubscriptionIssuedShares_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_SeriesA3PreferredStockSubscriptionIssuedShares" xml:lang="en-US" id="label_SeriesA3PreferredStockSubscriptionIssuedShares_3">Represents the number of shares of Series A-3 preferred stock subscription issued.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesA3PreferredStockSubscriptionIssuedShares" xlink:to="label_SeriesA3PreferredStockSubscriptionIssuedShares_3" xlink:title="label: SeriesA3PreferredStockSubscriptionIssuedShares to label_SeriesA3PreferredStockSubscriptionIssuedShares" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_SeriesA4PreferredStockSubscriptionIssuedValue" xlink:label="SeriesA4PreferredStockSubscriptionIssuedValue" xlink:title="SeriesA4PreferredStockSubscriptionIssuedValue" />
    <link:label xlink:type="resource" xlink:label="label_SeriesA4PreferredStockSubscriptionIssuedValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SeriesA4PreferredStockSubscriptionIssuedValue" xml:lang="en-US" id="label_SeriesA4PreferredStockSubscriptionIssuedValue">Series A4 Preferred Stock Subscription Issued Value</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesA4PreferredStockSubscriptionIssuedValue" xlink:to="label_SeriesA4PreferredStockSubscriptionIssuedValue" xlink:title="label: SeriesA4PreferredStockSubscriptionIssuedValue to label_SeriesA4PreferredStockSubscriptionIssuedValue" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesA4PreferredStockSubscriptionIssuedValue_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SeriesA4PreferredStockSubscriptionIssuedValue" xml:lang="en-US" id="label_SeriesA4PreferredStockSubscriptionIssuedValue_2">Proceeds from the sale of Series A-4 convertible preferred stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesA4PreferredStockSubscriptionIssuedValue" xlink:to="label_SeriesA4PreferredStockSubscriptionIssuedValue_2" xlink:title="label: SeriesA4PreferredStockSubscriptionIssuedValue to label_SeriesA4PreferredStockSubscriptionIssuedValue" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesA4PreferredStockSubscriptionIssuedValue_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_SeriesA4PreferredStockSubscriptionIssuedValue" xml:lang="en-US" id="label_SeriesA4PreferredStockSubscriptionIssuedValue_3">Represents the value of Series A-4 preferred stock subscription not issued.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesA4PreferredStockSubscriptionIssuedValue" xlink:to="label_SeriesA4PreferredStockSubscriptionIssuedValue_3" xlink:title="label: SeriesA4PreferredStockSubscriptionIssuedValue to label_SeriesA4PreferredStockSubscriptionIssuedValue" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_SeriesA4PreferredStockSubscriptionIssuedShares" xlink:label="SeriesA4PreferredStockSubscriptionIssuedShares" xlink:title="SeriesA4PreferredStockSubscriptionIssuedShares" />
    <link:label xlink:type="resource" xlink:label="label_SeriesA4PreferredStockSubscriptionIssuedShares" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SeriesA4PreferredStockSubscriptionIssuedShares" xml:lang="en-US" id="label_SeriesA4PreferredStockSubscriptionIssuedShares">Series A4 Preferred Stock Subscription Issued Shares</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesA4PreferredStockSubscriptionIssuedShares" xlink:to="label_SeriesA4PreferredStockSubscriptionIssuedShares" xlink:title="label: SeriesA4PreferredStockSubscriptionIssuedShares to label_SeriesA4PreferredStockSubscriptionIssuedShares" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesA4PreferredStockSubscriptionIssuedShares_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SeriesA4PreferredStockSubscriptionIssuedShares" xml:lang="en-US" id="label_SeriesA4PreferredStockSubscriptionIssuedShares_2">Proceeds from the sale of Series A-4 convertible preferred stock (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesA4PreferredStockSubscriptionIssuedShares" xlink:to="label_SeriesA4PreferredStockSubscriptionIssuedShares_2" xlink:title="label: SeriesA4PreferredStockSubscriptionIssuedShares to label_SeriesA4PreferredStockSubscriptionIssuedShares" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesA4PreferredStockSubscriptionIssuedShares_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_SeriesA4PreferredStockSubscriptionIssuedShares" xml:lang="en-US" id="label_SeriesA4PreferredStockSubscriptionIssuedShares_3">Represents the number of shares of Series A-4 preferred stock subscription issued.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesA4PreferredStockSubscriptionIssuedShares" xlink:to="label_SeriesA4PreferredStockSubscriptionIssuedShares_3" xlink:title="label: SeriesA4PreferredStockSubscriptionIssuedShares to label_SeriesA4PreferredStockSubscriptionIssuedShares" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_SeriesBPreferredStockSubscriptionIssuedValue" xlink:label="SeriesBPreferredStockSubscriptionIssuedValue" xlink:title="SeriesBPreferredStockSubscriptionIssuedValue" />
    <link:label xlink:type="resource" xlink:label="label_SeriesBPreferredStockSubscriptionIssuedValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SeriesBPreferredStockSubscriptionIssuedValue" xml:lang="en-US" id="label_SeriesBPreferredStockSubscriptionIssuedValue">Series B Preferred Stock Subscription Issued Value</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesBPreferredStockSubscriptionIssuedValue" xlink:to="label_SeriesBPreferredStockSubscriptionIssuedValue" xlink:title="label: SeriesBPreferredStockSubscriptionIssuedValue to label_SeriesBPreferredStockSubscriptionIssuedValue" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesBPreferredStockSubscriptionIssuedValue_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SeriesBPreferredStockSubscriptionIssuedValue" xml:lang="en-US" id="label_SeriesBPreferredStockSubscriptionIssuedValue_2">Proceeds from the sale of Series B convertible preferred stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesBPreferredStockSubscriptionIssuedValue" xlink:to="label_SeriesBPreferredStockSubscriptionIssuedValue_2" xlink:title="label: SeriesBPreferredStockSubscriptionIssuedValue to label_SeriesBPreferredStockSubscriptionIssuedValue" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesBPreferredStockSubscriptionIssuedValue_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_SeriesBPreferredStockSubscriptionIssuedValue" xml:lang="en-US" id="label_SeriesBPreferredStockSubscriptionIssuedValue_3">Represents the value of Series B preferred stock subscription not issued.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesBPreferredStockSubscriptionIssuedValue" xlink:to="label_SeriesBPreferredStockSubscriptionIssuedValue_3" xlink:title="label: SeriesBPreferredStockSubscriptionIssuedValue to label_SeriesBPreferredStockSubscriptionIssuedValue" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_SeriesBPreferredStockSubscriptionIssuedShares" xlink:label="SeriesBPreferredStockSubscriptionIssuedShares" xlink:title="SeriesBPreferredStockSubscriptionIssuedShares" />
    <link:label xlink:type="resource" xlink:label="label_SeriesBPreferredStockSubscriptionIssuedShares" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SeriesBPreferredStockSubscriptionIssuedShares" xml:lang="en-US" id="label_SeriesBPreferredStockSubscriptionIssuedShares">Series B Preferred Stock Subscription Issued Shares</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesBPreferredStockSubscriptionIssuedShares" xlink:to="label_SeriesBPreferredStockSubscriptionIssuedShares" xlink:title="label: SeriesBPreferredStockSubscriptionIssuedShares to label_SeriesBPreferredStockSubscriptionIssuedShares" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesBPreferredStockSubscriptionIssuedShares_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SeriesBPreferredStockSubscriptionIssuedShares" xml:lang="en-US" id="label_SeriesBPreferredStockSubscriptionIssuedShares_2">Proceeds from the sale of Series B convertible preferred stock (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesBPreferredStockSubscriptionIssuedShares" xlink:to="label_SeriesBPreferredStockSubscriptionIssuedShares_2" xlink:title="label: SeriesBPreferredStockSubscriptionIssuedShares to label_SeriesBPreferredStockSubscriptionIssuedShares" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesBPreferredStockSubscriptionIssuedShares_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_SeriesBPreferredStockSubscriptionIssuedShares" xml:lang="en-US" id="label_SeriesBPreferredStockSubscriptionIssuedShares_3">Represents the number of shares of Series B preferred stock subscription issued.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesBPreferredStockSubscriptionIssuedShares" xlink:to="label_SeriesBPreferredStockSubscriptionIssuedShares_3" xlink:title="label: SeriesBPreferredStockSubscriptionIssuedShares to label_SeriesBPreferredStockSubscriptionIssuedShares" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_StockIssuedDuringPeriodValuePreferredStock" xlink:label="StockIssuedDuringPeriodValuePreferredStock" xlink:title="StockIssuedDuringPeriodValuePreferredStock" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodValuePreferredStock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_StockIssuedDuringPeriodValuePreferredStock" xml:lang="en-US" id="label_StockIssuedDuringPeriodValuePreferredStock">Stock Issued During Period Value Preferred Stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodValuePreferredStock" xlink:to="label_StockIssuedDuringPeriodValuePreferredStock" xlink:title="label: StockIssuedDuringPeriodValuePreferredStock to label_StockIssuedDuringPeriodValuePreferredStock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodValuePreferredStock_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_StockIssuedDuringPeriodValuePreferredStock" xml:lang="en-US" id="label_StockIssuedDuringPeriodValuePreferredStock_2">Issuance of convertible preferred stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodValuePreferredStock" xlink:to="label_StockIssuedDuringPeriodValuePreferredStock_2" xlink:title="label: StockIssuedDuringPeriodValuePreferredStock to label_StockIssuedDuringPeriodValuePreferredStock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodValuePreferredStock_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_StockIssuedDuringPeriodValuePreferredStock" xml:lang="en-US" id="label_StockIssuedDuringPeriodValuePreferredStock_3">Represents the value of convertible preferred stock issued during the reporting period.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodValuePreferredStock" xlink:to="label_StockIssuedDuringPeriodValuePreferredStock_3" xlink:title="label: StockIssuedDuringPeriodValuePreferredStock to label_StockIssuedDuringPeriodValuePreferredStock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodValuePreferredStock_4" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_StockIssuedDuringPeriodValuePreferredStock" xml:lang="en-US" id="label_StockIssuedDuringPeriodValuePreferredStock_4">Total cash consideration for preferred stock issued and sold</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodValuePreferredStock" xlink:to="label_StockIssuedDuringPeriodValuePreferredStock_4" xlink:title="label: StockIssuedDuringPeriodValuePreferredStock to label_StockIssuedDuringPeriodValuePreferredStock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_StockIssuedDuringPeriodSharesPreferredStock" xlink:label="StockIssuedDuringPeriodSharesPreferredStock" xlink:title="StockIssuedDuringPeriodSharesPreferredStock" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodSharesPreferredStock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_StockIssuedDuringPeriodSharesPreferredStock" xml:lang="en-US" id="label_StockIssuedDuringPeriodSharesPreferredStock">Stock Issued During Period Shares Preferred Stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodSharesPreferredStock" xlink:to="label_StockIssuedDuringPeriodSharesPreferredStock" xlink:title="label: StockIssuedDuringPeriodSharesPreferredStock to label_StockIssuedDuringPeriodSharesPreferredStock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodSharesPreferredStock_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_StockIssuedDuringPeriodSharesPreferredStock" xml:lang="en-US" id="label_StockIssuedDuringPeriodSharesPreferredStock_2">Issuance of convertible preferred stock (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodSharesPreferredStock" xlink:to="label_StockIssuedDuringPeriodSharesPreferredStock_2" xlink:title="label: StockIssuedDuringPeriodSharesPreferredStock to label_StockIssuedDuringPeriodSharesPreferredStock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodSharesPreferredStock_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_StockIssuedDuringPeriodSharesPreferredStock" xml:lang="en-US" id="label_StockIssuedDuringPeriodSharesPreferredStock_3">Represents the number of shares of convertible preferred stock issued during the reporting period.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodSharesPreferredStock" xlink:to="label_StockIssuedDuringPeriodSharesPreferredStock_3" xlink:title="label: StockIssuedDuringPeriodSharesPreferredStock to label_StockIssuedDuringPeriodSharesPreferredStock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodSharesPreferredStock_4" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_StockIssuedDuringPeriodSharesPreferredStock" xml:lang="en-US" id="label_StockIssuedDuringPeriodSharesPreferredStock_4">Number of preferred stock issued and sold</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodSharesPreferredStock" xlink:to="label_StockIssuedDuringPeriodSharesPreferredStock_4" xlink:title="label: StockIssuedDuringPeriodSharesPreferredStock to label_StockIssuedDuringPeriodSharesPreferredStock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_StockIssuedDuringPeriodValueConversionOfSpecialParticipationStock" xlink:label="StockIssuedDuringPeriodValueConversionOfSpecialParticipationStock" xlink:title="StockIssuedDuringPeriodValueConversionOfSpecialParticipationStock" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodValueConversionOfSpecialParticipationStock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_StockIssuedDuringPeriodValueConversionOfSpecialParticipationStock" xml:lang="en-US" id="label_StockIssuedDuringPeriodValueConversionOfSpecialParticipationStock">Stock Issued During Period Value Conversion of Special Participation Stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodValueConversionOfSpecialParticipationStock" xlink:to="label_StockIssuedDuringPeriodValueConversionOfSpecialParticipationStock" xlink:title="label: StockIssuedDuringPeriodValueConversionOfSpecialParticipationStock to label_StockIssuedDuringPeriodValueConversionOfSpecialParticipationStock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodValueConversionOfSpecialParticipationStock_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_StockIssuedDuringPeriodValueConversionOfSpecialParticipationStock" xml:lang="en-US" id="label_StockIssuedDuringPeriodValueConversionOfSpecialParticipationStock_2">Settlement of special participation preferred shares</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodValueConversionOfSpecialParticipationStock" xlink:to="label_StockIssuedDuringPeriodValueConversionOfSpecialParticipationStock_2" xlink:title="label: StockIssuedDuringPeriodValueConversionOfSpecialParticipationStock to label_StockIssuedDuringPeriodValueConversionOfSpecialParticipationStock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodValueConversionOfSpecialParticipationStock_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_StockIssuedDuringPeriodValueConversionOfSpecialParticipationStock" xml:lang="en-US" id="label_StockIssuedDuringPeriodValueConversionOfSpecialParticipationStock_3">Represents the value of shares issued during the period upon the settlement of special participation stock.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodValueConversionOfSpecialParticipationStock" xlink:to="label_StockIssuedDuringPeriodValueConversionOfSpecialParticipationStock_3" xlink:title="label: StockIssuedDuringPeriodValueConversionOfSpecialParticipationStock to label_StockIssuedDuringPeriodValueConversionOfSpecialParticipationStock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_NumberOfAdvisors" xlink:label="NumberOfAdvisors" xlink:title="NumberOfAdvisors" />
    <link:label xlink:type="resource" xlink:label="label_NumberOfAdvisors" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_NumberOfAdvisors" xml:lang="en-US" id="label_NumberOfAdvisors">Number of Advisors</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="NumberOfAdvisors" xlink:to="label_NumberOfAdvisors" xlink:title="label: NumberOfAdvisors to label_NumberOfAdvisors" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_NumberOfAdvisors_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_NumberOfAdvisors" xml:lang="en-US" id="label_NumberOfAdvisors_2">Number of advisors</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="NumberOfAdvisors" xlink:to="label_NumberOfAdvisors_2" xlink:title="label: NumberOfAdvisors to label_NumberOfAdvisors" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_NumberOfAdvisors_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_NumberOfAdvisors" xml:lang="en-US" id="label_NumberOfAdvisors_3">Represents the number of advisors of the entity.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="NumberOfAdvisors" xlink:to="label_NumberOfAdvisors_3" xlink:title="label: NumberOfAdvisors to label_NumberOfAdvisors" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_NumberOfTranches" xlink:label="NumberOfTranches" xlink:title="NumberOfTranches" />
    <link:label xlink:type="resource" xlink:label="label_NumberOfTranches" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_NumberOfTranches" xml:lang="en-US" id="label_NumberOfTranches">Number of Tranches</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="NumberOfTranches" xlink:to="label_NumberOfTranches" xlink:title="label: NumberOfTranches to label_NumberOfTranches" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_NumberOfTranches_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_NumberOfTranches" xml:lang="en-US" id="label_NumberOfTranches_2">Number of tranches</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="NumberOfTranches" xlink:to="label_NumberOfTranches_2" xlink:title="label: NumberOfTranches to label_NumberOfTranches" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_NumberOfTranches_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_NumberOfTranches" xml:lang="en-US" id="label_NumberOfTranches_3">Represents the number of tranches in which stocks are issued.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="NumberOfTranches" xlink:to="label_NumberOfTranches_3" xlink:title="label: NumberOfTranches to label_NumberOfTranches" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_StockRepurchaseProgramNumberOfClosings" xlink:label="StockRepurchaseProgramNumberOfClosings" xlink:title="StockRepurchaseProgramNumberOfClosings" />
    <link:label xlink:type="resource" xlink:label="label_StockRepurchaseProgramNumberOfClosings" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_StockRepurchaseProgramNumberOfClosings" xml:lang="en-US" id="label_StockRepurchaseProgramNumberOfClosings">Stock Repurchase Program Number of Closings</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockRepurchaseProgramNumberOfClosings" xlink:to="label_StockRepurchaseProgramNumberOfClosings" xlink:title="label: StockRepurchaseProgramNumberOfClosings to label_StockRepurchaseProgramNumberOfClosings" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockRepurchaseProgramNumberOfClosings_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_StockRepurchaseProgramNumberOfClosings" xml:lang="en-US" id="label_StockRepurchaseProgramNumberOfClosings_2">Number of closings under stock purchase agreement</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockRepurchaseProgramNumberOfClosings" xlink:to="label_StockRepurchaseProgramNumberOfClosings_2" xlink:title="label: StockRepurchaseProgramNumberOfClosings to label_StockRepurchaseProgramNumberOfClosings" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockRepurchaseProgramNumberOfClosings_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_StockRepurchaseProgramNumberOfClosings" xml:lang="en-US" id="label_StockRepurchaseProgramNumberOfClosings_3">Represents the number of closings under the stock purchase agreement.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockRepurchaseProgramNumberOfClosings" xlink:to="label_StockRepurchaseProgramNumberOfClosings_3" xlink:title="label: StockRepurchaseProgramNumberOfClosings to label_StockRepurchaseProgramNumberOfClosings" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_StockAgreedToBeIssuedDuringPeriodSharesPreferredStock" xlink:label="StockAgreedToBeIssuedDuringPeriodSharesPreferredStock" xlink:title="StockAgreedToBeIssuedDuringPeriodSharesPreferredStock" />
    <link:label xlink:type="resource" xlink:label="label_StockAgreedToBeIssuedDuringPeriodSharesPreferredStock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_StockAgreedToBeIssuedDuringPeriodSharesPreferredStock" xml:lang="en-US" id="label_StockAgreedToBeIssuedDuringPeriodSharesPreferredStock">Stock Agreed to be Issued During Period Shares Preferred Stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockAgreedToBeIssuedDuringPeriodSharesPreferredStock" xlink:to="label_StockAgreedToBeIssuedDuringPeriodSharesPreferredStock" xlink:title="label: StockAgreedToBeIssuedDuringPeriodSharesPreferredStock to label_StockAgreedToBeIssuedDuringPeriodSharesPreferredStock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockAgreedToBeIssuedDuringPeriodSharesPreferredStock_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_StockAgreedToBeIssuedDuringPeriodSharesPreferredStock" xml:lang="en-US" id="label_StockAgreedToBeIssuedDuringPeriodSharesPreferredStock_2">Number of shares agreed to sell under the agreement</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockAgreedToBeIssuedDuringPeriodSharesPreferredStock" xlink:to="label_StockAgreedToBeIssuedDuringPeriodSharesPreferredStock_2" xlink:title="label: StockAgreedToBeIssuedDuringPeriodSharesPreferredStock to label_StockAgreedToBeIssuedDuringPeriodSharesPreferredStock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockAgreedToBeIssuedDuringPeriodSharesPreferredStock_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_StockAgreedToBeIssuedDuringPeriodSharesPreferredStock" xml:lang="en-US" id="label_StockAgreedToBeIssuedDuringPeriodSharesPreferredStock_3">Represents the number of shares agreed to be issued by the entity under the agreement.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockAgreedToBeIssuedDuringPeriodSharesPreferredStock" xlink:to="label_StockAgreedToBeIssuedDuringPeriodSharesPreferredStock_3" xlink:title="label: StockAgreedToBeIssuedDuringPeriodSharesPreferredStock to label_StockAgreedToBeIssuedDuringPeriodSharesPreferredStock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_StockAgreedToBeIssuedDuringPeriodValuePreferredStock" xlink:label="StockAgreedToBeIssuedDuringPeriodValuePreferredStock" xlink:title="StockAgreedToBeIssuedDuringPeriodValuePreferredStock" />
    <link:label xlink:type="resource" xlink:label="label_StockAgreedToBeIssuedDuringPeriodValuePreferredStock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_StockAgreedToBeIssuedDuringPeriodValuePreferredStock" xml:lang="en-US" id="label_StockAgreedToBeIssuedDuringPeriodValuePreferredStock">Stock Agreed to be Issued During Period Value Preferred Stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockAgreedToBeIssuedDuringPeriodValuePreferredStock" xlink:to="label_StockAgreedToBeIssuedDuringPeriodValuePreferredStock" xlink:title="label: StockAgreedToBeIssuedDuringPeriodValuePreferredStock to label_StockAgreedToBeIssuedDuringPeriodValuePreferredStock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockAgreedToBeIssuedDuringPeriodValuePreferredStock_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_StockAgreedToBeIssuedDuringPeriodValuePreferredStock" xml:lang="en-US" id="label_StockAgreedToBeIssuedDuringPeriodValuePreferredStock_2">Value of shares agreed to sell under the agreement</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockAgreedToBeIssuedDuringPeriodValuePreferredStock" xlink:to="label_StockAgreedToBeIssuedDuringPeriodValuePreferredStock_2" xlink:title="label: StockAgreedToBeIssuedDuringPeriodValuePreferredStock to label_StockAgreedToBeIssuedDuringPeriodValuePreferredStock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockAgreedToBeIssuedDuringPeriodValuePreferredStock_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_StockAgreedToBeIssuedDuringPeriodValuePreferredStock" xml:lang="en-US" id="label_StockAgreedToBeIssuedDuringPeriodValuePreferredStock_3">Represents the value of shares agreed to be issued by the entity under the agreement.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockAgreedToBeIssuedDuringPeriodValuePreferredStock" xlink:to="label_StockAgreedToBeIssuedDuringPeriodValuePreferredStock_3" xlink:title="label: StockAgreedToBeIssuedDuringPeriodValuePreferredStock to label_StockAgreedToBeIssuedDuringPeriodValuePreferredStock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_NumberOfAdditionalSharesObligatedToPurchaseByExistingInvestors" xlink:label="NumberOfAdditionalSharesObligatedToPurchaseByExistingInvestors" xlink:title="NumberOfAdditionalSharesObligatedToPurchaseByExistingInvestors" />
    <link:label xlink:type="resource" xlink:label="label_NumberOfAdditionalSharesObligatedToPurchaseByExistingInvestors" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_NumberOfAdditionalSharesObligatedToPurchaseByExistingInvestors" xml:lang="en-US" id="label_NumberOfAdditionalSharesObligatedToPurchaseByExistingInvestors">Number of Additional Shares Obligated to Purchase by Existing Investors</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="NumberOfAdditionalSharesObligatedToPurchaseByExistingInvestors" xlink:to="label_NumberOfAdditionalSharesObligatedToPurchaseByExistingInvestors" xlink:title="label: NumberOfAdditionalSharesObligatedToPurchaseByExistingInvestors to label_NumberOfAdditionalSharesObligatedToPurchaseByExistingInvestors" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_NumberOfAdditionalSharesObligatedToPurchaseByExistingInvestors_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_NumberOfAdditionalSharesObligatedToPurchaseByExistingInvestors" xml:lang="en-US" id="label_NumberOfAdditionalSharesObligatedToPurchaseByExistingInvestors_2">Number of additional shares obligated to purchase by the existing investors</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="NumberOfAdditionalSharesObligatedToPurchaseByExistingInvestors" xlink:to="label_NumberOfAdditionalSharesObligatedToPurchaseByExistingInvestors_2" xlink:title="label: NumberOfAdditionalSharesObligatedToPurchaseByExistingInvestors to label_NumberOfAdditionalSharesObligatedToPurchaseByExistingInvestors" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_NumberOfAdditionalSharesObligatedToPurchaseByExistingInvestors_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_NumberOfAdditionalSharesObligatedToPurchaseByExistingInvestors" xml:lang="en-US" id="label_NumberOfAdditionalSharesObligatedToPurchaseByExistingInvestors_3">Represents the number of additional shares obligated to purchase by the existing investors of the entity.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="NumberOfAdditionalSharesObligatedToPurchaseByExistingInvestors" xlink:to="label_NumberOfAdditionalSharesObligatedToPurchaseByExistingInvestors_3" xlink:title="label: NumberOfAdditionalSharesObligatedToPurchaseByExistingInvestors to label_NumberOfAdditionalSharesObligatedToPurchaseByExistingInvestors" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_ValueOfAdditionalSharesObligatedToPurchaseByExistingInvestors" xlink:label="ValueOfAdditionalSharesObligatedToPurchaseByExistingInvestors" xlink:title="ValueOfAdditionalSharesObligatedToPurchaseByExistingInvestors" />
    <link:label xlink:type="resource" xlink:label="label_ValueOfAdditionalSharesObligatedToPurchaseByExistingInvestors" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ValueOfAdditionalSharesObligatedToPurchaseByExistingInvestors" xml:lang="en-US" id="label_ValueOfAdditionalSharesObligatedToPurchaseByExistingInvestors">Value of Additional Shares Obligated to Purchase by Existing Investors</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ValueOfAdditionalSharesObligatedToPurchaseByExistingInvestors" xlink:to="label_ValueOfAdditionalSharesObligatedToPurchaseByExistingInvestors" xlink:title="label: ValueOfAdditionalSharesObligatedToPurchaseByExistingInvestors to label_ValueOfAdditionalSharesObligatedToPurchaseByExistingInvestors" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ValueOfAdditionalSharesObligatedToPurchaseByExistingInvestors_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ValueOfAdditionalSharesObligatedToPurchaseByExistingInvestors" xml:lang="en-US" id="label_ValueOfAdditionalSharesObligatedToPurchaseByExistingInvestors_2">Proceeds from additional shares issued, which was obligated to purchase by the existing investors</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ValueOfAdditionalSharesObligatedToPurchaseByExistingInvestors" xlink:to="label_ValueOfAdditionalSharesObligatedToPurchaseByExistingInvestors_2" xlink:title="label: ValueOfAdditionalSharesObligatedToPurchaseByExistingInvestors to label_ValueOfAdditionalSharesObligatedToPurchaseByExistingInvestors" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ValueOfAdditionalSharesObligatedToPurchaseByExistingInvestors_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_ValueOfAdditionalSharesObligatedToPurchaseByExistingInvestors" xml:lang="en-US" id="label_ValueOfAdditionalSharesObligatedToPurchaseByExistingInvestors_3">Represents the proceeds from additional shares issued, which was obligated to purchase by the existing investors of the entity.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ValueOfAdditionalSharesObligatedToPurchaseByExistingInvestors" xlink:to="label_ValueOfAdditionalSharesObligatedToPurchaseByExistingInvestors_3" xlink:title="label: ValueOfAdditionalSharesObligatedToPurchaseByExistingInvestors to label_ValueOfAdditionalSharesObligatedToPurchaseByExistingInvestors" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_SpecialParticipationStockNumberOfSharesAuthorizedForIssuance" xlink:label="SpecialParticipationStockNumberOfSharesAuthorizedForIssuance" xlink:title="SpecialParticipationStockNumberOfSharesAuthorizedForIssuance" />
    <link:label xlink:type="resource" xlink:label="label_SpecialParticipationStockNumberOfSharesAuthorizedForIssuance" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SpecialParticipationStockNumberOfSharesAuthorizedForIssuance" xml:lang="en-US" id="label_SpecialParticipationStockNumberOfSharesAuthorizedForIssuance">Special Participation Stock Number of Shares Authorized for Issuance</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SpecialParticipationStockNumberOfSharesAuthorizedForIssuance" xlink:to="label_SpecialParticipationStockNumberOfSharesAuthorizedForIssuance" xlink:title="label: SpecialParticipationStockNumberOfSharesAuthorizedForIssuance to label_SpecialParticipationStockNumberOfSharesAuthorizedForIssuance" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SpecialParticipationStockNumberOfSharesAuthorizedForIssuance_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SpecialParticipationStockNumberOfSharesAuthorizedForIssuance" xml:lang="en-US" id="label_SpecialParticipationStockNumberOfSharesAuthorizedForIssuance_2">Number of shares of Special Participation Stock authorized for issuance</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SpecialParticipationStockNumberOfSharesAuthorizedForIssuance" xlink:to="label_SpecialParticipationStockNumberOfSharesAuthorizedForIssuance_2" xlink:title="label: SpecialParticipationStockNumberOfSharesAuthorizedForIssuance to label_SpecialParticipationStockNumberOfSharesAuthorizedForIssuance" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SpecialParticipationStockNumberOfSharesAuthorizedForIssuance_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_SpecialParticipationStockNumberOfSharesAuthorizedForIssuance" xml:lang="en-US" id="label_SpecialParticipationStockNumberOfSharesAuthorizedForIssuance_3">Represents the number of shares of special participation stock authorized for issuance during the period.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SpecialParticipationStockNumberOfSharesAuthorizedForIssuance" xlink:to="label_SpecialParticipationStockNumberOfSharesAuthorizedForIssuance_3" xlink:title="label: SpecialParticipationStockNumberOfSharesAuthorizedForIssuance to label_SpecialParticipationStockNumberOfSharesAuthorizedForIssuance" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_SpecialParticipationStockNumberOfSharesOutstanding" xlink:label="SpecialParticipationStockNumberOfSharesOutstanding" xlink:title="SpecialParticipationStockNumberOfSharesOutstanding" />
    <link:label xlink:type="resource" xlink:label="label_SpecialParticipationStockNumberOfSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SpecialParticipationStockNumberOfSharesOutstanding" xml:lang="en-US" id="label_SpecialParticipationStockNumberOfSharesOutstanding">Special Participation Stock Number of Shares Outstanding</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SpecialParticipationStockNumberOfSharesOutstanding" xlink:to="label_SpecialParticipationStockNumberOfSharesOutstanding" xlink:title="label: SpecialParticipationStockNumberOfSharesOutstanding to label_SpecialParticipationStockNumberOfSharesOutstanding" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SpecialParticipationStockNumberOfSharesOutstanding_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SpecialParticipationStockNumberOfSharesOutstanding" xml:lang="en-US" id="label_SpecialParticipationStockNumberOfSharesOutstanding_2">Outstanding shares of Special Participation Stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SpecialParticipationStockNumberOfSharesOutstanding" xlink:to="label_SpecialParticipationStockNumberOfSharesOutstanding_2" xlink:title="label: SpecialParticipationStockNumberOfSharesOutstanding to label_SpecialParticipationStockNumberOfSharesOutstanding" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SpecialParticipationStockNumberOfSharesOutstanding_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_SpecialParticipationStockNumberOfSharesOutstanding" xml:lang="en-US" id="label_SpecialParticipationStockNumberOfSharesOutstanding_3">Represents the number of shares of special participation stock outstanding as of the balance sheet date.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SpecialParticipationStockNumberOfSharesOutstanding" xlink:to="label_SpecialParticipationStockNumberOfSharesOutstanding_3" xlink:title="label: SpecialParticipationStockNumberOfSharesOutstanding to label_SpecialParticipationStockNumberOfSharesOutstanding" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_SeriesAConvertiblePreferredStockTrancheOneMember" xlink:label="SeriesAConvertiblePreferredStockTrancheOneMember" xlink:title="SeriesAConvertiblePreferredStockTrancheOneMember" />
    <link:label xlink:type="resource" xlink:label="label_SeriesAConvertiblePreferredStockTrancheOneMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SeriesAConvertiblePreferredStockTrancheOneMember" xml:lang="en-US" id="label_SeriesAConvertiblePreferredStockTrancheOneMember">Series A preferred stock tranche one</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesAConvertiblePreferredStockTrancheOneMember" xlink:to="label_SeriesAConvertiblePreferredStockTrancheOneMember" xlink:title="label: SeriesAConvertiblePreferredStockTrancheOneMember to label_SeriesAConvertiblePreferredStockTrancheOneMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesAConvertiblePreferredStockTrancheOneMember_2" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_SeriesAConvertiblePreferredStockTrancheOneMember" xml:lang="en-US" id="label_SeriesAConvertiblePreferredStockTrancheOneMember_2">Represents information pertaining to the tranche one of Series A convertible preferred stock.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesAConvertiblePreferredStockTrancheOneMember" xlink:to="label_SeriesAConvertiblePreferredStockTrancheOneMember_2" xlink:title="label: SeriesAConvertiblePreferredStockTrancheOneMember to label_SeriesAConvertiblePreferredStockTrancheOneMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesAConvertiblePreferredStockTrancheOneMember_3" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SeriesAConvertiblePreferredStockTrancheOneMember" xml:lang="en-US" id="label_SeriesAConvertiblePreferredStockTrancheOneMember_3">Series A Convertible Preferred Stock Tranche One [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesAConvertiblePreferredStockTrancheOneMember" xlink:to="label_SeriesAConvertiblePreferredStockTrancheOneMember_3" xlink:title="label: SeriesAConvertiblePreferredStockTrancheOneMember to label_SeriesAConvertiblePreferredStockTrancheOneMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_SeriesAConvertiblePreferredStockTrancheTwoMember" xlink:label="SeriesAConvertiblePreferredStockTrancheTwoMember" xlink:title="SeriesAConvertiblePreferredStockTrancheTwoMember" />
    <link:label xlink:type="resource" xlink:label="label_SeriesAConvertiblePreferredStockTrancheTwoMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SeriesAConvertiblePreferredStockTrancheTwoMember" xml:lang="en-US" id="label_SeriesAConvertiblePreferredStockTrancheTwoMember">Series A Convertible Preferred Stock Tranche Two [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesAConvertiblePreferredStockTrancheTwoMember" xlink:to="label_SeriesAConvertiblePreferredStockTrancheTwoMember" xlink:title="label: SeriesAConvertiblePreferredStockTrancheTwoMember to label_SeriesAConvertiblePreferredStockTrancheTwoMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesAConvertiblePreferredStockTrancheTwoMember_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SeriesAConvertiblePreferredStockTrancheTwoMember" xml:lang="en-US" id="label_SeriesAConvertiblePreferredStockTrancheTwoMember_2">Series A preferred stock tranche two</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesAConvertiblePreferredStockTrancheTwoMember" xlink:to="label_SeriesAConvertiblePreferredStockTrancheTwoMember_2" xlink:title="label: SeriesAConvertiblePreferredStockTrancheTwoMember to label_SeriesAConvertiblePreferredStockTrancheTwoMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SeriesAConvertiblePreferredStockTrancheTwoMember_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_SeriesAConvertiblePreferredStockTrancheTwoMember" xml:lang="en-US" id="label_SeriesAConvertiblePreferredStockTrancheTwoMember_3">Represents information pertaining to the tranche two of Series A convertible preferred stock.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SeriesAConvertiblePreferredStockTrancheTwoMember" xlink:to="label_SeriesAConvertiblePreferredStockTrancheTwoMember_3" xlink:title="label: SeriesAConvertiblePreferredStockTrancheTwoMember to label_SeriesAConvertiblePreferredStockTrancheTwoMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_FoundersMember" xlink:label="FoundersMember" xlink:title="FoundersMember" />
    <link:label xlink:type="resource" xlink:label="label_FoundersMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_FoundersMember" xml:lang="en-US" id="label_FoundersMember">Founders [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="FoundersMember" xlink:to="label_FoundersMember" xlink:title="label: FoundersMember to label_FoundersMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_FoundersMember_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_FoundersMember" xml:lang="en-US" id="label_FoundersMember_2">Founders</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="FoundersMember" xlink:to="label_FoundersMember_2" xlink:title="label: FoundersMember to label_FoundersMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_FoundersMember_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_FoundersMember" xml:lang="en-US" id="label_FoundersMember_3">Represents information pertaining to founders of the entity.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="FoundersMember" xlink:to="label_FoundersMember_3" xlink:title="label: FoundersMember to label_FoundersMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_AdvisorsMember" xlink:label="AdvisorsMember" xlink:title="AdvisorsMember" />
    <link:label xlink:type="resource" xlink:label="label_AdvisorsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AdvisorsMember" xml:lang="en-US" id="label_AdvisorsMember">Advisors [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AdvisorsMember" xlink:to="label_AdvisorsMember" xlink:title="label: AdvisorsMember to label_AdvisorsMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_AdvisorsMember_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_AdvisorsMember" xml:lang="en-US" id="label_AdvisorsMember_2">Advisors</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AdvisorsMember" xlink:to="label_AdvisorsMember_2" xlink:title="label: AdvisorsMember to label_AdvisorsMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_AdvisorsMember_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_AdvisorsMember" xml:lang="en-US" id="label_AdvisorsMember_3">Represents information pertaining to advisors of the entity.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AdvisorsMember" xlink:to="label_AdvisorsMember_3" xlink:title="label: AdvisorsMember to label_AdvisorsMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_AccruedResearchAndDevelopmentCostsCurrent" xlink:label="AccruedResearchAndDevelopmentCostsCurrent" xlink:title="AccruedResearchAndDevelopmentCostsCurrent" />
    <link:label xlink:type="resource" xlink:label="label_AccruedResearchAndDevelopmentCostsCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_AccruedResearchAndDevelopmentCostsCurrent" xml:lang="en-US" id="label_AccruedResearchAndDevelopmentCostsCurrent">Research and development costs</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AccruedResearchAndDevelopmentCostsCurrent" xlink:to="label_AccruedResearchAndDevelopmentCostsCurrent" xlink:title="label: AccruedResearchAndDevelopmentCostsCurrent to label_AccruedResearchAndDevelopmentCostsCurrent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_AccruedResearchAndDevelopmentCostsCurrent_2" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_AccruedResearchAndDevelopmentCostsCurrent" xml:lang="en-US" id="label_AccruedResearchAndDevelopmentCostsCurrent_2">Carrying value as of the balance sheet date of obligations incurred through that date and payable for research and development costs. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AccruedResearchAndDevelopmentCostsCurrent" xlink:to="label_AccruedResearchAndDevelopmentCostsCurrent_2" xlink:title="label: AccruedResearchAndDevelopmentCostsCurrent to label_AccruedResearchAndDevelopmentCostsCurrent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_AccruedResearchAndDevelopmentCostsCurrent_3" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AccruedResearchAndDevelopmentCostsCurrent" xml:lang="en-US" id="label_AccruedResearchAndDevelopmentCostsCurrent_3">Accrued Research and Development Costs, Current</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AccruedResearchAndDevelopmentCostsCurrent" xlink:to="label_AccruedResearchAndDevelopmentCostsCurrent_3" xlink:title="label: AccruedResearchAndDevelopmentCostsCurrent to label_AccruedResearchAndDevelopmentCostsCurrent" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_DocumentAndEntityInformationAbstract" xlink:label="DocumentAndEntityInformationAbstract" xlink:title="DocumentAndEntityInformationAbstract" />
    <link:label xlink:type="resource" xlink:label="label_DocumentAndEntityInformationAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_DocumentAndEntityInformationAbstract" xml:lang="en-US" id="label_DocumentAndEntityInformationAbstract">Document and Entity Information</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DocumentAndEntityInformationAbstract" xlink:to="label_DocumentAndEntityInformationAbstract" xlink:title="label: DocumentAndEntityInformationAbstract to label_DocumentAndEntityInformationAbstract" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_EmployeeAndNonemployeeStockOptionMember" xlink:label="EmployeeAndNonemployeeStockOptionMember" xlink:title="EmployeeAndNonemployeeStockOptionMember" />
    <link:label xlink:type="resource" xlink:label="label_EmployeeAndNonemployeeStockOptionMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_EmployeeAndNonemployeeStockOptionMember" xml:lang="en-US" id="label_EmployeeAndNonemployeeStockOptionMember">Employee and Nonemployee Stock Option [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EmployeeAndNonemployeeStockOptionMember" xlink:to="label_EmployeeAndNonemployeeStockOptionMember" xlink:title="label: EmployeeAndNonemployeeStockOptionMember to label_EmployeeAndNonemployeeStockOptionMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_EmployeeAndNonemployeeStockOptionMember_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_EmployeeAndNonemployeeStockOptionMember" xml:lang="en-US" id="label_EmployeeAndNonemployeeStockOptionMember_2">Stock options</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EmployeeAndNonemployeeStockOptionMember" xlink:to="label_EmployeeAndNonemployeeStockOptionMember_2" xlink:title="label: EmployeeAndNonemployeeStockOptionMember to label_EmployeeAndNonemployeeStockOptionMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_EmployeeAndNonemployeeStockOptionMember_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_EmployeeAndNonemployeeStockOptionMember" xml:lang="en-US" id="label_EmployeeAndNonemployeeStockOptionMember_3">Represents information pertaining to the stock options allotted to employees and non-employees.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EmployeeAndNonemployeeStockOptionMember" xlink:to="label_EmployeeAndNonemployeeStockOptionMember_3" xlink:title="label: EmployeeAndNonemployeeStockOptionMember to label_EmployeeAndNonemployeeStockOptionMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_IncreaseDecreaseInAccruedLiabilitiesAndOtherLiabilities" xlink:label="IncreaseDecreaseInAccruedLiabilitiesAndOtherLiabilities" xlink:title="IncreaseDecreaseInAccruedLiabilitiesAndOtherLiabilities" />
    <link:label xlink:type="resource" xlink:label="label_IncreaseDecreaseInAccruedLiabilitiesAndOtherLiabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_IncreaseDecreaseInAccruedLiabilitiesAndOtherLiabilities" xml:lang="en-US" id="label_IncreaseDecreaseInAccruedLiabilitiesAndOtherLiabilities">Increase (Decrease) in Accrued Liabilities and Other Liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="IncreaseDecreaseInAccruedLiabilitiesAndOtherLiabilities" xlink:to="label_IncreaseDecreaseInAccruedLiabilitiesAndOtherLiabilities" xlink:title="label: IncreaseDecreaseInAccruedLiabilitiesAndOtherLiabilities to label_IncreaseDecreaseInAccruedLiabilitiesAndOtherLiabilities" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_IncreaseDecreaseInAccruedLiabilitiesAndOtherLiabilities_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_IncreaseDecreaseInAccruedLiabilitiesAndOtherLiabilities" xml:lang="en-US" id="label_IncreaseDecreaseInAccruedLiabilitiesAndOtherLiabilities_2">Accrued expenses and other liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="IncreaseDecreaseInAccruedLiabilitiesAndOtherLiabilities" xlink:to="label_IncreaseDecreaseInAccruedLiabilitiesAndOtherLiabilities_2" xlink:title="label: IncreaseDecreaseInAccruedLiabilitiesAndOtherLiabilities to label_IncreaseDecreaseInAccruedLiabilitiesAndOtherLiabilities" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_IncreaseDecreaseInAccruedLiabilitiesAndOtherLiabilities_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_IncreaseDecreaseInAccruedLiabilitiesAndOtherLiabilities" xml:lang="en-US" id="label_IncreaseDecreaseInAccruedLiabilitiesAndOtherLiabilities_3">The increase (decrease) during the reporting period in the aggregate amount of expenses incurred but not yet paid and other liabilities used in operating activities not separately disclosed.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="IncreaseDecreaseInAccruedLiabilitiesAndOtherLiabilities" xlink:to="label_IncreaseDecreaseInAccruedLiabilitiesAndOtherLiabilities_3" xlink:title="label: IncreaseDecreaseInAccruedLiabilitiesAndOtherLiabilities to label_IncreaseDecreaseInAccruedLiabilitiesAndOtherLiabilities" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_NoncashConsultingExpense" xlink:label="NoncashConsultingExpense" xlink:title="NoncashConsultingExpense" />
    <link:label xlink:type="resource" xlink:label="label_NoncashConsultingExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_NoncashConsultingExpense" xml:lang="en-US" id="label_NoncashConsultingExpense">Noncash Consulting Expense</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="NoncashConsultingExpense" xlink:to="label_NoncashConsultingExpense" xlink:title="label: NoncashConsultingExpense to label_NoncashConsultingExpense" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_NoncashConsultingExpense_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_NoncashConsultingExpense" xml:lang="en-US" id="label_NoncashConsultingExpense_2">Noncash consulting expense</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="NoncashConsultingExpense" xlink:to="label_NoncashConsultingExpense_2" xlink:title="label: NoncashConsultingExpense to label_NoncashConsultingExpense" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_NoncashConsultingExpense_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_NoncashConsultingExpense" xml:lang="en-US" id="label_NoncashConsultingExpense_3">Represents the amount of consulting expense included in net income that resulted in no cash outflows or inflows in the period and is not separately disclosed.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="NoncashConsultingExpense" xlink:to="label_NoncashConsultingExpense_3" xlink:title="label: NoncashConsultingExpense to label_NoncashConsultingExpense" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_PreferredStockSubscriptionMember" xlink:label="PreferredStockSubscriptionMember" xlink:title="PreferredStockSubscriptionMember" />
    <link:label xlink:type="resource" xlink:label="label_PreferredStockSubscriptionMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_PreferredStockSubscriptionMember" xml:lang="en-US" id="label_PreferredStockSubscriptionMember">Preferred Stock Subscription [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PreferredStockSubscriptionMember" xlink:to="label_PreferredStockSubscriptionMember" xlink:title="label: PreferredStockSubscriptionMember to label_PreferredStockSubscriptionMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_PreferredStockSubscriptionMember_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_PreferredStockSubscriptionMember" xml:lang="en-US" id="label_PreferredStockSubscriptionMember_2">Preferred Stock Subscription</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PreferredStockSubscriptionMember" xlink:to="label_PreferredStockSubscriptionMember_2" xlink:title="label: PreferredStockSubscriptionMember to label_PreferredStockSubscriptionMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_PreferredStockSubscriptionMember_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_PreferredStockSubscriptionMember" xml:lang="en-US" id="label_PreferredStockSubscriptionMember_3">Represents information pertaining to the new issue of securities classified as temporary equity which are allocated to the investors. When securities are sold on a subscription basis, the issuer does not initially receive the total proceeds.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PreferredStockSubscriptionMember" xlink:to="label_PreferredStockSubscriptionMember_3" xlink:title="label: PreferredStockSubscriptionMember to label_PreferredStockSubscriptionMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_StockIncentiveExcludingPlan2010Member" xlink:label="StockIncentiveExcludingPlan2010Member" xlink:title="StockIncentiveExcludingPlan2010Member" />
    <link:label xlink:type="resource" xlink:label="label_StockIncentiveExcludingPlan2010Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_StockIncentiveExcludingPlan2010Member" xml:lang="en-US" id="label_StockIncentiveExcludingPlan2010Member">Stock Incentive excluding Plan 2010 [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIncentiveExcludingPlan2010Member" xlink:to="label_StockIncentiveExcludingPlan2010Member" xlink:title="label: StockIncentiveExcludingPlan2010Member to label_StockIncentiveExcludingPlan2010Member" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIncentiveExcludingPlan2010Member_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_StockIncentiveExcludingPlan2010Member" xml:lang="en-US" id="label_StockIncentiveExcludingPlan2010Member_2">Outside of the Plan</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIncentiveExcludingPlan2010Member" xlink:to="label_StockIncentiveExcludingPlan2010Member_2" xlink:title="label: StockIncentiveExcludingPlan2010Member to label_StockIncentiveExcludingPlan2010Member" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIncentiveExcludingPlan2010Member_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_StockIncentiveExcludingPlan2010Member" xml:lang="en-US" id="label_StockIncentiveExcludingPlan2010Member_3">Represents information pertaining to the outside of the 2010 Stock Incentive Plan.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIncentiveExcludingPlan2010Member" xlink:to="label_StockIncentiveExcludingPlan2010Member_3" xlink:title="label: StockIncentiveExcludingPlan2010Member to label_StockIncentiveExcludingPlan2010Member" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_RevenueRecognitionMilestoneMethodNumberOfFutureMilestonesToBeMet" xlink:label="RevenueRecognitionMilestoneMethodNumberOfFutureMilestonesToBeMet" xlink:title="RevenueRecognitionMilestoneMethodNumberOfFutureMilestonesToBeMet" />
    <link:label xlink:type="resource" xlink:label="label_RevenueRecognitionMilestoneMethodNumberOfFutureMilestonesToBeMet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_RevenueRecognitionMilestoneMethodNumberOfFutureMilestonesToBeMet" xml:lang="en-US" id="label_RevenueRecognitionMilestoneMethodNumberOfFutureMilestonesToBeMet">Revenue Recognition Milestone Method Number of Future Milestones to be Met</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="RevenueRecognitionMilestoneMethodNumberOfFutureMilestonesToBeMet" xlink:to="label_RevenueRecognitionMilestoneMethodNumberOfFutureMilestonesToBeMet" xlink:title="label: RevenueRecognitionMilestoneMethodNumberOfFutureMilestonesToBeMet to label_RevenueRecognitionMilestoneMethodNumberOfFutureMilestonesToBeMet" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_RevenueRecognitionMilestoneMethodNumberOfFutureMilestonesToBeMet_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_RevenueRecognitionMilestoneMethodNumberOfFutureMilestonesToBeMet" xml:lang="en-US" id="label_RevenueRecognitionMilestoneMethodNumberOfFutureMilestonesToBeMet_2">Number of future milestones to be met</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="RevenueRecognitionMilestoneMethodNumberOfFutureMilestonesToBeMet" xlink:to="label_RevenueRecognitionMilestoneMethodNumberOfFutureMilestonesToBeMet_2" xlink:title="label: RevenueRecognitionMilestoneMethodNumberOfFutureMilestonesToBeMet to label_RevenueRecognitionMilestoneMethodNumberOfFutureMilestonesToBeMet" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_RevenueRecognitionMilestoneMethodNumberOfFutureMilestonesToBeMet_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_RevenueRecognitionMilestoneMethodNumberOfFutureMilestonesToBeMet" xml:lang="en-US" id="label_RevenueRecognitionMilestoneMethodNumberOfFutureMilestonesToBeMet_3">Represents the number of future milestones to be met for recognition of revenue as per milestone method of revenue recognition.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="RevenueRecognitionMilestoneMethodNumberOfFutureMilestonesToBeMet" xlink:to="label_RevenueRecognitionMilestoneMethodNumberOfFutureMilestonesToBeMet_3" xlink:title="label: RevenueRecognitionMilestoneMethodNumberOfFutureMilestonesToBeMet to label_RevenueRecognitionMilestoneMethodNumberOfFutureMilestonesToBeMet" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_TemporaryEquitySubscriptionsAndCarryingAmountAttributableToParent" xlink:label="TemporaryEquitySubscriptionsAndCarryingAmountAttributableToParent" xlink:title="TemporaryEquitySubscriptionsAndCarryingAmountAttributableToParent" />
    <link:label xlink:type="resource" xlink:label="label_TemporaryEquitySubscriptionsAndCarryingAmountAttributableToParent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_TemporaryEquitySubscriptionsAndCarryingAmountAttributableToParent" xml:lang="en-US" id="label_TemporaryEquitySubscriptionsAndCarryingAmountAttributableToParent">Temporary Equity Subscriptions and Carrying Amount Attributable to Parent</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TemporaryEquitySubscriptionsAndCarryingAmountAttributableToParent" xlink:to="label_TemporaryEquitySubscriptionsAndCarryingAmountAttributableToParent" xlink:title="label: TemporaryEquitySubscriptionsAndCarryingAmountAttributableToParent to label_TemporaryEquitySubscriptionsAndCarryingAmountAttributableToParent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_TemporaryEquitySubscriptionsAndCarryingAmountAttributableToParent_2" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:title="label_TemporaryEquitySubscriptionsAndCarryingAmountAttributableToParent" xml:lang="en-US" id="label_TemporaryEquitySubscriptionsAndCarryingAmountAttributableToParent_2">Total convertible preferred stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TemporaryEquitySubscriptionsAndCarryingAmountAttributableToParent" xlink:to="label_TemporaryEquitySubscriptionsAndCarryingAmountAttributableToParent_2" xlink:title="label: TemporaryEquitySubscriptionsAndCarryingAmountAttributableToParent to label_TemporaryEquitySubscriptionsAndCarryingAmountAttributableToParent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_TemporaryEquitySubscriptionsAndCarryingAmountAttributableToParent_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_TemporaryEquitySubscriptionsAndCarryingAmountAttributableToParent" xml:lang="en-US" id="label_TemporaryEquitySubscriptionsAndCarryingAmountAttributableToParent_3">Represents the aggregate amount of securities classified as temporary equity that have been allocated to investors to buy as well as carrying amount, attributable to parent, of an entity's issued and outstanding stock which is not included within permanent equity. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TemporaryEquitySubscriptionsAndCarryingAmountAttributableToParent" xlink:to="label_TemporaryEquitySubscriptionsAndCarryingAmountAttributableToParent_3" xlink:title="label: TemporaryEquitySubscriptionsAndCarryingAmountAttributableToParent to label_TemporaryEquitySubscriptionsAndCarryingAmountAttributableToParent" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_RoyaltyAndSublicensePayment" xlink:label="RoyaltyAndSublicensePayment" xlink:title="RoyaltyAndSublicensePayment" />
    <link:label xlink:type="resource" xlink:label="label_RoyaltyAndSublicensePayment" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_RoyaltyAndSublicensePayment" xml:lang="en-US" id="label_RoyaltyAndSublicensePayment">Royalty and Sublicense Payment</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="RoyaltyAndSublicensePayment" xlink:to="label_RoyaltyAndSublicensePayment" xlink:title="label: RoyaltyAndSublicensePayment to label_RoyaltyAndSublicensePayment" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_RoyaltyAndSublicensePayment_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_RoyaltyAndSublicensePayment" xml:lang="en-US" id="label_RoyaltyAndSublicensePayment_2">Royalty and Sublicense payment</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="RoyaltyAndSublicensePayment" xlink:to="label_RoyaltyAndSublicensePayment_2" xlink:title="label: RoyaltyAndSublicensePayment to label_RoyaltyAndSublicensePayment" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_RoyaltyAndSublicensePayment_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_RoyaltyAndSublicensePayment" xml:lang="en-US" id="label_RoyaltyAndSublicensePayment_3">Represent total amount of royalty payments made under contractual arrangement on product sale or sublicense income, up to predetermined maximum.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="RoyaltyAndSublicensePayment" xlink:to="label_RoyaltyAndSublicensePayment_3" xlink:title="label: RoyaltyAndSublicensePayment to label_RoyaltyAndSublicensePayment" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_OperatingLeasesAllowanceForImprovements" xlink:label="OperatingLeasesAllowanceForImprovements" xlink:title="OperatingLeasesAllowanceForImprovements" />
    <link:label xlink:type="resource" xlink:label="label_OperatingLeasesAllowanceForImprovements" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_OperatingLeasesAllowanceForImprovements" xml:lang="en-US" id="label_OperatingLeasesAllowanceForImprovements">Operating Leases Allowance for Improvements</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingLeasesAllowanceForImprovements" xlink:to="label_OperatingLeasesAllowanceForImprovements" xlink:title="label: OperatingLeasesAllowanceForImprovements to label_OperatingLeasesAllowanceForImprovements" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OperatingLeasesAllowanceForImprovements_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_OperatingLeasesAllowanceForImprovements" xml:lang="en-US" id="label_OperatingLeasesAllowanceForImprovements_2">Allowance for improvements</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingLeasesAllowanceForImprovements" xlink:to="label_OperatingLeasesAllowanceForImprovements_2" xlink:title="label: OperatingLeasesAllowanceForImprovements to label_OperatingLeasesAllowanceForImprovements" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OperatingLeasesAllowanceForImprovements_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_OperatingLeasesAllowanceForImprovements" xml:lang="en-US" id="label_OperatingLeasesAllowanceForImprovements_3">Represents the amount of operating lease that provides the company with an allowance for the improvement.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingLeasesAllowanceForImprovements" xlink:to="label_OperatingLeasesAllowanceForImprovements_3" xlink:title="label: OperatingLeasesAllowanceForImprovements to label_OperatingLeasesAllowanceForImprovements" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_AmountOfOperatingLeaseForWhichAllowanceForImprovementsIsProvided" xlink:label="AmountOfOperatingLeaseForWhichAllowanceForImprovementsIsProvided" xlink:title="AmountOfOperatingLeaseForWhichAllowanceForImprovementsIsProvided" />
    <link:label xlink:type="resource" xlink:label="label_AmountOfOperatingLeaseForWhichAllowanceForImprovementsIsProvided" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_AmountOfOperatingLeaseForWhichAllowanceForImprovementsIsProvided" xml:lang="en-US" id="label_AmountOfOperatingLeaseForWhichAllowanceForImprovementsIsProvided">Amount of operating lease for which allowance for improvements is provided</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AmountOfOperatingLeaseForWhichAllowanceForImprovementsIsProvided" xlink:to="label_AmountOfOperatingLeaseForWhichAllowanceForImprovementsIsProvided" xlink:title="label: AmountOfOperatingLeaseForWhichAllowanceForImprovementsIsProvided to label_AmountOfOperatingLeaseForWhichAllowanceForImprovementsIsProvided" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_AmountOfOperatingLeaseForWhichAllowanceForImprovementsIsProvided_2" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_AmountOfOperatingLeaseForWhichAllowanceForImprovementsIsProvided" xml:lang="en-US" id="label_AmountOfOperatingLeaseForWhichAllowanceForImprovementsIsProvided_2">Represents the amount of operating lease for which allowance for improvements is provided during the period.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AmountOfOperatingLeaseForWhichAllowanceForImprovementsIsProvided" xlink:to="label_AmountOfOperatingLeaseForWhichAllowanceForImprovementsIsProvided_2" xlink:title="label: AmountOfOperatingLeaseForWhichAllowanceForImprovementsIsProvided to label_AmountOfOperatingLeaseForWhichAllowanceForImprovementsIsProvided" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_AmountOfOperatingLeaseForWhichAllowanceForImprovementsIsProvided_3" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AmountOfOperatingLeaseForWhichAllowanceForImprovementsIsProvided" xml:lang="en-US" id="label_AmountOfOperatingLeaseForWhichAllowanceForImprovementsIsProvided_3">Amount of Operating Lease for which Allowance for Improvements is Provided</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AmountOfOperatingLeaseForWhichAllowanceForImprovementsIsProvided" xlink:to="label_AmountOfOperatingLeaseForWhichAllowanceForImprovementsIsProvided_3" xlink:title="label: AmountOfOperatingLeaseForWhichAllowanceForImprovementsIsProvided to label_AmountOfOperatingLeaseForWhichAllowanceForImprovementsIsProvided" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_AnnualInterestRate" xlink:label="AnnualInterestRate" xlink:title="AnnualInterestRate" />
    <link:label xlink:type="resource" xlink:label="label_AnnualInterestRate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AnnualInterestRate" xml:lang="en-US" id="label_AnnualInterestRate">Annual Interest Rate</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AnnualInterestRate" xlink:to="label_AnnualInterestRate" xlink:title="label: AnnualInterestRate to label_AnnualInterestRate" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_AnnualInterestRate_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_AnnualInterestRate" xml:lang="en-US" id="label_AnnualInterestRate_2">Annual interest rate (as a percent)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AnnualInterestRate" xlink:to="label_AnnualInterestRate_2" xlink:title="label: AnnualInterestRate to label_AnnualInterestRate" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_AnnualInterestRate_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_AnnualInterestRate" xml:lang="en-US" id="label_AnnualInterestRate_3">Represents the operating lease annual interest rate.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AnnualInterestRate" xlink:to="label_AnnualInterestRate_3" xlink:title="label: AnnualInterestRate to label_AnnualInterestRate" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_SecurityDepositWhichMayBeReducedInFuture" xlink:label="SecurityDepositWhichMayBeReducedInFuture" xlink:title="SecurityDepositWhichMayBeReducedInFuture" />
    <link:label xlink:type="resource" xlink:label="label_SecurityDepositWhichMayBeReducedInFuture" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SecurityDepositWhichMayBeReducedInFuture" xml:lang="en-US" id="label_SecurityDepositWhichMayBeReducedInFuture">Security Deposit which May be Reduced in Future</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SecurityDepositWhichMayBeReducedInFuture" xlink:to="label_SecurityDepositWhichMayBeReducedInFuture" xlink:title="label: SecurityDepositWhichMayBeReducedInFuture to label_SecurityDepositWhichMayBeReducedInFuture" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SecurityDepositWhichMayBeReducedInFuture_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SecurityDepositWhichMayBeReducedInFuture" xml:lang="en-US" id="label_SecurityDepositWhichMayBeReducedInFuture_2">Security deposit in the form of a letter of credit which may be reduced in January 2018.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SecurityDepositWhichMayBeReducedInFuture" xlink:to="label_SecurityDepositWhichMayBeReducedInFuture_2" xlink:title="label: SecurityDepositWhichMayBeReducedInFuture to label_SecurityDepositWhichMayBeReducedInFuture" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SecurityDepositWhichMayBeReducedInFuture_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_SecurityDepositWhichMayBeReducedInFuture" xml:lang="en-US" id="label_SecurityDepositWhichMayBeReducedInFuture_3">Represents the amount of an asset, typically cash, provided to a counterparty to provide certain assurance of performance by the entity pursuant to the terms of a written or oral agreement, such as a lease which maybe reduced in future.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SecurityDepositWhichMayBeReducedInFuture" xlink:to="label_SecurityDepositWhichMayBeReducedInFuture_3" xlink:title="label: SecurityDepositWhichMayBeReducedInFuture to label_SecurityDepositWhichMayBeReducedInFuture" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_OperatingLeaseScheduledRentPaymentsDue" xlink:label="OperatingLeaseScheduledRentPaymentsDue" xlink:title="OperatingLeaseScheduledRentPaymentsDue" />
    <link:label xlink:type="resource" xlink:label="label_OperatingLeaseScheduledRentPaymentsDue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_OperatingLeaseScheduledRentPaymentsDue" xml:lang="en-US" id="label_OperatingLeaseScheduledRentPaymentsDue">Operating Lease Scheduled Rent Payments Due</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingLeaseScheduledRentPaymentsDue" xlink:to="label_OperatingLeaseScheduledRentPaymentsDue" xlink:title="label: OperatingLeaseScheduledRentPaymentsDue to label_OperatingLeaseScheduledRentPaymentsDue" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OperatingLeaseScheduledRentPaymentsDue_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_OperatingLeaseScheduledRentPaymentsDue" xml:lang="en-US" id="label_OperatingLeaseScheduledRentPaymentsDue_2">Scheduled rent payments due</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingLeaseScheduledRentPaymentsDue" xlink:to="label_OperatingLeaseScheduledRentPaymentsDue_2" xlink:title="label: OperatingLeaseScheduledRentPaymentsDue to label_OperatingLeaseScheduledRentPaymentsDue" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OperatingLeaseScheduledRentPaymentsDue_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_OperatingLeaseScheduledRentPaymentsDue" xml:lang="en-US" id="label_OperatingLeaseScheduledRentPaymentsDue_3">Represents the amount of operating lease scheduled rent payments due during the period.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingLeaseScheduledRentPaymentsDue" xlink:to="label_OperatingLeaseScheduledRentPaymentsDue_3" xlink:title="label: OperatingLeaseScheduledRentPaymentsDue to label_OperatingLeaseScheduledRentPaymentsDue" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_IncreaseDecreaseInDeferredRent" xlink:label="IncreaseDecreaseInDeferredRent" xlink:title="IncreaseDecreaseInDeferredRent" />
    <link:label xlink:type="resource" xlink:label="label_IncreaseDecreaseInDeferredRent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_IncreaseDecreaseInDeferredRent" xml:lang="en-US" id="label_IncreaseDecreaseInDeferredRent">Increase (Decrease) in Deferred Rent</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="IncreaseDecreaseInDeferredRent" xlink:to="label_IncreaseDecreaseInDeferredRent" xlink:title="label: IncreaseDecreaseInDeferredRent to label_IncreaseDecreaseInDeferredRent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_IncreaseDecreaseInDeferredRent_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_IncreaseDecreaseInDeferredRent" xml:lang="en-US" id="label_IncreaseDecreaseInDeferredRent_2">Deferred rent</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="IncreaseDecreaseInDeferredRent" xlink:to="label_IncreaseDecreaseInDeferredRent_2" xlink:title="label: IncreaseDecreaseInDeferredRent to label_IncreaseDecreaseInDeferredRent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_IncreaseDecreaseInDeferredRent_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_IncreaseDecreaseInDeferredRent" xml:lang="en-US" id="label_IncreaseDecreaseInDeferredRent_3">The Increase (decrease) during the reporting period in the amount due that is the result of cumulative difference between the payments required by a lease agreement and the rental income or expense recognized on a straight-line basis, or other systematic and rational basis more representative of the time pattern in which use or benefit is granted or derived from the leased property.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="IncreaseDecreaseInDeferredRent" xlink:to="label_IncreaseDecreaseInDeferredRent_3" xlink:title="label: IncreaseDecreaseInDeferredRent to label_IncreaseDecreaseInDeferredRent" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_EmployeeStockPurchasePIanMember" xlink:label="EmployeeStockPurchasePIanMember" xlink:title="EmployeeStockPurchasePIanMember" />
    <link:label xlink:type="resource" xlink:label="label_EmployeeStockPurchasePIanMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_EmployeeStockPurchasePIanMember" xml:lang="en-US" id="label_EmployeeStockPurchasePIanMember">Employee Stock Purchase PIan [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EmployeeStockPurchasePIanMember" xlink:to="label_EmployeeStockPurchasePIanMember" xlink:title="label: EmployeeStockPurchasePIanMember to label_EmployeeStockPurchasePIanMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_EmployeeStockPurchasePIanMember_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_EmployeeStockPurchasePIanMember" xml:lang="en-US" id="label_EmployeeStockPurchasePIanMember_2">ESPP</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EmployeeStockPurchasePIanMember" xlink:to="label_EmployeeStockPurchasePIanMember_2" xlink:title="label: EmployeeStockPurchasePIanMember to label_EmployeeStockPurchasePIanMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_EmployeeStockPurchasePIanMember_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_EmployeeStockPurchasePIanMember" xml:lang="en-US" id="label_EmployeeStockPurchasePIanMember_3">Represents information pertaining to employee stock purchase plan.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EmployeeStockPurchasePIanMember" xlink:to="label_EmployeeStockPurchasePIanMember_3" xlink:title="label: EmployeeStockPurchasePIanMember to label_EmployeeStockPurchasePIanMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityWellKnownSeasonedIssuer" xlink:label="EntityWellKnownSeasonedIssuer" xlink:title="EntityWellKnownSeasonedIssuer" />
    <link:label xlink:type="resource" xlink:label="label_EntityWellKnownSeasonedIssuer" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_EntityWellKnownSeasonedIssuer" xml:lang="en-US" id="label_EntityWellKnownSeasonedIssuer">Entity Well-known Seasoned Issuer</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EntityWellKnownSeasonedIssuer" xlink:to="label_EntityWellKnownSeasonedIssuer" xlink:title="label: EntityWellKnownSeasonedIssuer to label_EntityWellKnownSeasonedIssuer" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod">Share Based Compensation Arrangement by Share Based Payment Award Offering Period</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod_2">Offering period</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod_2" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod_3">Represents the offering period of awards under the share based compensation plan.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod_3" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityVoluntaryFilers" xlink:label="EntityVoluntaryFilers" xlink:title="EntityVoluntaryFilers" />
    <link:label xlink:type="resource" xlink:label="label_EntityVoluntaryFilers" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_EntityVoluntaryFilers" xml:lang="en-US" id="label_EntityVoluntaryFilers">Entity Voluntary Filers</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EntityVoluntaryFilers" xlink:to="label_EntityVoluntaryFilers" xlink:title="label: EntityVoluntaryFilers to label_EntityVoluntaryFilers" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPurchasePeriod" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPurchasePeriod" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPurchasePeriod" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPurchasePeriod" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPurchasePeriod" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPurchasePeriod">Share Based Compensation Arrangement by Share Based Payment Award Number of Purchase Period</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPurchasePeriod" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPurchasePeriod" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPurchasePeriod to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPurchasePeriod" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPurchasePeriod_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPurchasePeriod" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPurchasePeriod_2">Number of purchase period</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPurchasePeriod" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPurchasePeriod_2" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPurchasePeriod to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPurchasePeriod" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPurchasePeriod_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPurchasePeriod" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPurchasePeriod_3">Represents the number of purchase period for awards under the share based compensation plan.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPurchasePeriod" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPurchasePeriod_3" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPurchasePeriod to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPurchasePeriod" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityCurrentReportingStatus" xlink:label="EntityCurrentReportingStatus" xlink:title="EntityCurrentReportingStatus" />
    <link:label xlink:type="resource" xlink:label="label_EntityCurrentReportingStatus" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_EntityCurrentReportingStatus" xml:lang="en-US" id="label_EntityCurrentReportingStatus">Entity Current Reporting Status</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EntityCurrentReportingStatus" xlink:to="label_EntityCurrentReportingStatus" xlink:title="label: EntityCurrentReportingStatus to label_EntityCurrentReportingStatus" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePeriod" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePeriod" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePeriod" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePeriod" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePeriod" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePeriod">Share Based Compensation Arrangement by Share Based Payment Award Purchase Period</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePeriod" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePeriod" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePeriod to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePeriod" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePeriod_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePeriod" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePeriod_2">Purchase period</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePeriod" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePeriod_2" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePeriod to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePeriod" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePeriod_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePeriod" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePeriod_3">Represents the purchase period of awards under the share based compensation plan.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePeriod" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePeriod_3" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePeriod to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePeriod" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityFilerCategory" xlink:label="EntityFilerCategory" xlink:title="EntityFilerCategory" />
    <link:label xlink:type="resource" xlink:label="label_EntityFilerCategory" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_EntityFilerCategory" xml:lang="en-US" id="label_EntityFilerCategory">Entity Filer Category</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EntityFilerCategory" xlink:to="label_EntityFilerCategory" xlink:title="label: EntityFilerCategory to label_EntityFilerCategory" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_LesseeLeasingArrangementsOperatingLeasesNumberOfAdditionalLeaseTerm" xlink:label="LesseeLeasingArrangementsOperatingLeasesNumberOfAdditionalLeaseTerm" xlink:title="LesseeLeasingArrangementsOperatingLeasesNumberOfAdditionalLeaseTerm" />
    <link:label xlink:type="resource" xlink:label="label_LesseeLeasingArrangementsOperatingLeasesNumberOfAdditionalLeaseTerm" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_LesseeLeasingArrangementsOperatingLeasesNumberOfAdditionalLeaseTerm" xml:lang="en-US" id="label_LesseeLeasingArrangementsOperatingLeasesNumberOfAdditionalLeaseTerm">Lessee Leasing Arrangements Operating Leases Number of Additional Lease Term</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="LesseeLeasingArrangementsOperatingLeasesNumberOfAdditionalLeaseTerm" xlink:to="label_LesseeLeasingArrangementsOperatingLeasesNumberOfAdditionalLeaseTerm" xlink:title="label: LesseeLeasingArrangementsOperatingLeasesNumberOfAdditionalLeaseTerm to label_LesseeLeasingArrangementsOperatingLeasesNumberOfAdditionalLeaseTerm" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_LesseeLeasingArrangementsOperatingLeasesNumberOfAdditionalLeaseTerm_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_LesseeLeasingArrangementsOperatingLeasesNumberOfAdditionalLeaseTerm" xml:lang="en-US" id="label_LesseeLeasingArrangementsOperatingLeasesNumberOfAdditionalLeaseTerm_2">Number of additional lease term</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="LesseeLeasingArrangementsOperatingLeasesNumberOfAdditionalLeaseTerm" xlink:to="label_LesseeLeasingArrangementsOperatingLeasesNumberOfAdditionalLeaseTerm_2" xlink:title="label: LesseeLeasingArrangementsOperatingLeasesNumberOfAdditionalLeaseTerm to label_LesseeLeasingArrangementsOperatingLeasesNumberOfAdditionalLeaseTerm" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_LesseeLeasingArrangementsOperatingLeasesNumberOfAdditionalLeaseTerm_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_LesseeLeasingArrangementsOperatingLeasesNumberOfAdditionalLeaseTerm" xml:lang="en-US" id="label_LesseeLeasingArrangementsOperatingLeasesNumberOfAdditionalLeaseTerm_3">Represents the number of additional term for which lease can be extend.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="LesseeLeasingArrangementsOperatingLeasesNumberOfAdditionalLeaseTerm" xlink:to="label_LesseeLeasingArrangementsOperatingLeasesNumberOfAdditionalLeaseTerm_3" xlink:title="label: LesseeLeasingArrangementsOperatingLeasesNumberOfAdditionalLeaseTerm to label_LesseeLeasingArrangementsOperatingLeasesNumberOfAdditionalLeaseTerm" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityPublicFloat" xlink:label="EntityPublicFloat" xlink:title="EntityPublicFloat" />
    <link:label xlink:type="resource" xlink:label="label_EntityPublicFloat" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_EntityPublicFloat" xml:lang="en-US" id="label_EntityPublicFloat">Entity Public Float</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EntityPublicFloat" xlink:to="label_EntityPublicFloat" xlink:title="label: EntityPublicFloat to label_EntityPublicFloat" use="optional" />
    <link:loc xlink:type="locator" xlink:href="kpti-20140630.xsd#kpti_LesseeLeasingArrangementsOperatingLeasesAdditionalExtensionTerm" xlink:label="LesseeLeasingArrangementsOperatingLeasesAdditionalExtensionTerm" xlink:title="LesseeLeasingArrangementsOperatingLeasesAdditionalExtensionTerm" />
    <link:label xlink:type="resource" xlink:label="label_LesseeLeasingArrangementsOperatingLeasesAdditionalExtensionTerm" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_LesseeLeasingArrangementsOperatingLeasesAdditionalExtensionTerm" xml:lang="en-US" id="label_LesseeLeasingArrangementsOperatingLeasesAdditionalExtensionTerm">Lessee Leasing Arrangements Operating Leases Additional Extension Term</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="LesseeLeasingArrangementsOperatingLeasesAdditionalExtensionTerm" xlink:to="label_LesseeLeasingArrangementsOperatingLeasesAdditionalExtensionTerm" xlink:title="label: LesseeLeasingArrangementsOperatingLeasesAdditionalExtensionTerm to label_LesseeLeasingArrangementsOperatingLeasesAdditionalExtensionTerm" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_LesseeLeasingArrangementsOperatingLeasesAdditionalExtensionTerm_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_LesseeLeasingArrangementsOperatingLeasesAdditionalExtensionTerm" xml:lang="en-US" id="label_LesseeLeasingArrangementsOperatingLeasesAdditionalExtensionTerm_2">Additional extension term of lease</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="LesseeLeasingArrangementsOperatingLeasesAdditionalExtensionTerm" xlink:to="label_LesseeLeasingArrangementsOperatingLeasesAdditionalExtensionTerm_2" xlink:title="label: LesseeLeasingArrangementsOperatingLeasesAdditionalExtensionTerm to label_LesseeLeasingArrangementsOperatingLeasesAdditionalExtensionTerm" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_LesseeLeasingArrangementsOperatingLeasesAdditionalExtensionTerm_3" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:title="label_LesseeLeasingArrangementsOperatingLeasesAdditionalExtensionTerm" xml:lang="en-US" id="label_LesseeLeasingArrangementsOperatingLeasesAdditionalExtensionTerm_3">Represents the additional term for which lease can be extend under the lessee's leasing arrangement.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="LesseeLeasingArrangementsOperatingLeasesAdditionalExtensionTerm" xlink:to="label_LesseeLeasingArrangementsOperatingLeasesAdditionalExtensionTerm_3" xlink:title="label: LesseeLeasingArrangementsOperatingLeasesAdditionalExtensionTerm to label_LesseeLeasingArrangementsOperatingLeasesAdditionalExtensionTerm" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityRegistrantName" xlink:label="EntityRegistrantName" xlink:title="EntityRegistrantName" />
    <link:label xlink:type="resource" xlink:label="label_EntityRegistrantName" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_EntityRegistrantName" xml:lang="en-US" id="label_EntityRegistrantName">Entity Registrant Name</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EntityRegistrantName" xlink:to="label_EntityRegistrantName" xlink:title="label: EntityRegistrantName to label_EntityRegistrantName" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityCentralIndexKey" xlink:label="EntityCentralIndexKey" xlink:title="EntityCentralIndexKey" />
    <link:label xlink:type="resource" xlink:label="label_EntityCentralIndexKey" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_EntityCentralIndexKey" xml:lang="en-US" id="label_EntityCentralIndexKey">Entity Central Index Key</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EntityCentralIndexKey" xlink:to="label_EntityCentralIndexKey" xlink:title="label: EntityCentralIndexKey to label_EntityCentralIndexKey" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="EntityCommonStockSharesOutstanding" xlink:title="EntityCommonStockSharesOutstanding" />
    <link:label xlink:type="resource" xlink:label="label_EntityCommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_EntityCommonStockSharesOutstanding" xml:lang="en-US" id="label_EntityCommonStockSharesOutstanding">Entity Common Stock, Shares Outstanding</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EntityCommonStockSharesOutstanding" xlink:to="label_EntityCommonStockSharesOutstanding" xlink:title="label: EntityCommonStockSharesOutstanding to label_EntityCommonStockSharesOutstanding" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_DocumentFiscalYearFocus" xlink:label="DocumentFiscalYearFocus" xlink:title="DocumentFiscalYearFocus" />
    <link:label xlink:type="resource" xlink:label="label_DocumentFiscalYearFocus" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_DocumentFiscalYearFocus" xml:lang="en-US" id="label_DocumentFiscalYearFocus">Document Fiscal Year Focus</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DocumentFiscalYearFocus" xlink:to="label_DocumentFiscalYearFocus" xlink:title="label: DocumentFiscalYearFocus to label_DocumentFiscalYearFocus" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="DocumentFiscalPeriodFocus" xlink:title="DocumentFiscalPeriodFocus" />
    <link:label xlink:type="resource" xlink:label="label_DocumentFiscalPeriodFocus" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_DocumentFiscalPeriodFocus" xml:lang="en-US" id="label_DocumentFiscalPeriodFocus">Document Fiscal Period Focus</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DocumentFiscalPeriodFocus" xlink:to="label_DocumentFiscalPeriodFocus" xlink:title="label: DocumentFiscalPeriodFocus to label_DocumentFiscalPeriodFocus" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:label="LegalEntityAxis" xlink:title="LegalEntityAxis" />
    <link:label xlink:type="resource" xlink:label="label_LegalEntityAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_LegalEntityAxis" xml:lang="en-US" id="label_LegalEntityAxis">Legal Entity [Axis]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="LegalEntityAxis" xlink:to="label_LegalEntityAxis" xlink:title="label: LegalEntityAxis to label_LegalEntityAxis" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_DocumentType" xlink:label="DocumentType" xlink:title="DocumentType" />
    <link:label xlink:type="resource" xlink:label="label_DocumentType" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_DocumentType" xml:lang="en-US" id="label_DocumentType">Document Type</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DocumentType" xlink:to="label_DocumentType" xlink:title="label: DocumentType to label_DocumentType" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="AccountingPoliciesAbstract" xlink:title="AccountingPoliciesAbstract" />
    <link:label xlink:type="resource" xlink:label="label_AccountingPoliciesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AccountingPoliciesAbstract" xml:lang="en-US" id="label_AccountingPoliciesAbstract">Summary of Significant Accounting Policies</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AccountingPoliciesAbstract" xlink:to="label_AccountingPoliciesAbstract" xlink:title="label: AccountingPoliciesAbstract to label_AccountingPoliciesAbstract" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock" xlink:label="AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock" xlink:title="AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock" xml:lang="en-US" id="label_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock">Accrued Expenses</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock" xlink:to="label_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock" xlink:title="label: AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock to label_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock" xml:lang="en-US" id="label_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock_2">Accounts Payable and Accrued Liabilities Disclosure [Text Block]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock" xlink:to="label_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock_2" xlink:title="label: AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock to label_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="AccountsPayableCurrent" xlink:title="AccountsPayableCurrent" />
    <link:label xlink:type="resource" xlink:label="label_AccountsPayableCurrent" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_AccountsPayableCurrent" xml:lang="en-US" id="label_AccountsPayableCurrent">Accounts payable (NPM restricted December 31, 2012 $499)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AccountsPayableCurrent" xlink:to="label_AccountsPayableCurrent" xlink:title="label: AccountsPayableCurrent to label_AccountsPayableCurrent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_AccountsPayableCurrent_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AccountsPayableCurrent" xml:lang="en-US" id="label_AccountsPayableCurrent_2">Accounts Payable, Current</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AccountsPayableCurrent" xlink:to="label_AccountsPayableCurrent_2" xlink:title="label: AccountsPayableCurrent to label_AccountsPayableCurrent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_AccountsPayableCurrent_3" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_AccountsPayableCurrent" xml:lang="en-US" id="label_AccountsPayableCurrent_3">Accounts payable (in dollars)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AccountsPayableCurrent" xlink:to="label_AccountsPayableCurrent_3" xlink:title="label: AccountsPayableCurrent to label_AccountsPayableCurrent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_AccountsPayableCurrent_4" xlink:role="http://www.xbrl.org/2003/role/positiveLabel" xlink:title="label_AccountsPayableCurrent" xml:lang="en-US" id="label_AccountsPayableCurrent_4">Accounts payable</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AccountsPayableCurrent" xlink:to="label_AccountsPayableCurrent_4" xlink:title="label: AccountsPayableCurrent to label_AccountsPayableCurrent" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccruedLiabilitiesCurrentAbstract" xlink:label="AccruedLiabilitiesCurrentAbstract" xlink:title="AccruedLiabilitiesCurrentAbstract" />
    <link:label xlink:type="resource" xlink:label="label_AccruedLiabilitiesCurrentAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AccruedLiabilitiesCurrentAbstract" xml:lang="en-US" id="label_AccruedLiabilitiesCurrentAbstract">Accrued Expenses</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AccruedLiabilitiesCurrentAbstract" xlink:to="label_AccruedLiabilitiesCurrentAbstract" xlink:title="label: AccruedLiabilitiesCurrentAbstract to label_AccruedLiabilitiesCurrentAbstract" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="AccruedLiabilitiesCurrent" xlink:title="AccruedLiabilitiesCurrent" />
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AccruedLiabilitiesCurrent" xlink:to="label_AccruedLiabilitiesCurrent" xlink:title="label: AccruedLiabilitiesCurrent to label_AccruedLiabilitiesCurrent" use="optional" />
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AccruedLiabilitiesCurrent" xlink:to="label_AccruedLiabilitiesCurrent_2" xlink:title="label: AccruedLiabilitiesCurrent to label_AccruedLiabilitiesCurrent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_AccruedLiabilitiesCurrent_3" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_AccruedLiabilitiesCurrent" xml:lang="en-US" id="label_AccruedLiabilitiesCurrent_3">Accrued expenses (NPM restricted December 31, 2012 $312)</link:label>
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    <link:label xlink:type="resource" xlink:label="label_AccruedLiabilitiesCurrent_4" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_AccruedLiabilitiesCurrent" xml:lang="en-US" id="label_AccruedLiabilitiesCurrent_4">Accrued expenses</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AccruedLiabilitiesCurrent" xlink:to="label_AccruedLiabilitiesCurrent_4" xlink:title="label: AccruedLiabilitiesCurrent to label_AccruedLiabilitiesCurrent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_AccruedLiabilitiesCurrent_5" xlink:role="http://www.xbrl.org/2003/role/positiveLabel" xlink:title="label_AccruedLiabilitiesCurrent" xml:lang="en-US" id="label_AccruedLiabilitiesCurrent_5">Accrued expenses and other liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AccruedLiabilitiesCurrent" xlink:to="label_AccruedLiabilitiesCurrent_5" xlink:title="label: AccruedLiabilitiesCurrent to label_AccruedLiabilitiesCurrent" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccruedProfessionalFeesCurrent" xlink:label="AccruedProfessionalFeesCurrent" xlink:title="AccruedProfessionalFeesCurrent" />
    <link:label xlink:type="resource" xlink:label="label_AccruedProfessionalFeesCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_AccruedProfessionalFeesCurrent" xml:lang="en-US" id="label_AccruedProfessionalFeesCurrent">Professional fees</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AccruedProfessionalFeesCurrent" xlink:to="label_AccruedProfessionalFeesCurrent" xlink:title="label: AccruedProfessionalFeesCurrent to label_AccruedProfessionalFeesCurrent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_AccruedProfessionalFeesCurrent_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AccruedProfessionalFeesCurrent" xml:lang="en-US" id="label_AccruedProfessionalFeesCurrent_2">Accrued Professional Fees, Current</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AccruedProfessionalFeesCurrent" xlink:to="label_AccruedProfessionalFeesCurrent_2" xlink:title="label: AccruedProfessionalFeesCurrent to label_AccruedProfessionalFeesCurrent" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:title="AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" />
    <link:label xlink:type="resource" xlink:label="label_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:title="label_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xml:lang="en-US" id="label_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment">Less accumulated depreciation and amortization</link:label>
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    <link:label xlink:type="resource" xlink:label="label_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xml:lang="en-US" id="label_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_2">Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccumulatedDeficitDuringDevelopmentStageMember" xlink:label="AccumulatedDeficitDuringDevelopmentStageMember" xlink:title="AccumulatedDeficitDuringDevelopmentStageMember" />
    <link:label xlink:type="resource" xlink:label="label_AccumulatedDeficitDuringDevelopmentStageMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AccumulatedDeficitDuringDevelopmentStageMember" xml:lang="en-US" id="label_AccumulatedDeficitDuringDevelopmentStageMember">Accumulated Deficit during Development Stage [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AccumulatedDeficitDuringDevelopmentStageMember" xlink:to="label_AccumulatedDeficitDuringDevelopmentStageMember" xlink:title="label: AccumulatedDeficitDuringDevelopmentStageMember to label_AccumulatedDeficitDuringDevelopmentStageMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_AccumulatedDeficitDuringDevelopmentStageMember_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_AccumulatedDeficitDuringDevelopmentStageMember" xml:lang="en-US" id="label_AccumulatedDeficitDuringDevelopmentStageMember_2">Deficit Accumulated During the Development Stage</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AccumulatedDeficitDuringDevelopmentStageMember" xlink:to="label_AccumulatedDeficitDuringDevelopmentStageMember_2" xlink:title="label: AccumulatedDeficitDuringDevelopmentStageMember to label_AccumulatedDeficitDuringDevelopmentStageMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="AdditionalPaidInCapital" xlink:title="AdditionalPaidInCapital" />
    <link:label xlink:type="resource" xlink:label="label_AdditionalPaidInCapital" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_AdditionalPaidInCapital" xml:lang="en-US" id="label_AdditionalPaidInCapital">Additional paid-in capital</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AdditionalPaidInCapital" xlink:to="label_AdditionalPaidInCapital" xlink:title="label: AdditionalPaidInCapital to label_AdditionalPaidInCapital" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_AdditionalPaidInCapital_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AdditionalPaidInCapital" xml:lang="en-US" id="label_AdditionalPaidInCapital_2">Additional Paid in Capital</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AdditionalPaidInCapital" xlink:to="label_AdditionalPaidInCapital_2" xlink:title="label: AdditionalPaidInCapital to label_AdditionalPaidInCapital" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="AdditionalPaidInCapitalMember" xlink:title="AdditionalPaidInCapitalMember" />
    <link:label xlink:type="resource" xlink:label="label_AdditionalPaidInCapitalMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AdditionalPaidInCapitalMember" xml:lang="en-US" id="label_AdditionalPaidInCapitalMember">Additional Paid-in Capital [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AdditionalPaidInCapitalMember" xlink:to="label_AdditionalPaidInCapitalMember" xlink:title="label: AdditionalPaidInCapitalMember to label_AdditionalPaidInCapitalMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_AdditionalPaidInCapitalMember_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_AdditionalPaidInCapitalMember" xml:lang="en-US" id="label_AdditionalPaidInCapitalMember_2">Additional Paid-In Capital</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AdditionalPaidInCapitalMember" xlink:to="label_AdditionalPaidInCapitalMember_2" xlink:title="label: AdditionalPaidInCapitalMember to label_AdditionalPaidInCapitalMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:title="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" />
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    <link:label xlink:type="resource" xlink:label="label_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xml:lang="en-US" id="label_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_2">Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:label="AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:title="AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" />
    <link:label xlink:type="resource" xlink:label="label_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xml:lang="en-US" id="label_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue">Stock-based compensation expense</link:label>
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    <link:label xlink:type="resource" xlink:label="label_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xml:lang="en-US" id="label_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_2">Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationRestrictedStockUnitsRequisiteServicePeriodRecognition" xlink:label="AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationRestrictedStockUnitsRequisiteServicePeriodRecognition" xlink:title="AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationRestrictedStockUnitsRequisiteServicePeriodRecognition" />
    <link:label xlink:type="resource" xlink:label="label_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationRestrictedStockUnitsRequisiteServicePeriodRecognition" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationRestrictedStockUnitsRequisiteServicePeriodRecognition" xml:lang="en-US" id="label_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationRestrictedStockUnitsRequisiteServicePeriodRecognition">Proceeds from sale of restricted stock to advisors</link:label>
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    <link:label xlink:type="resource" xlink:label="label_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationRestrictedStockUnitsRequisiteServicePeriodRecognition_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationRestrictedStockUnitsRequisiteServicePeriodRecognition" xml:lang="en-US" id="label_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationRestrictedStockUnitsRequisiteServicePeriodRecognition_2">Adjustments to Additional Paid in Capital, Share-based Compensation, Restricted Stock Unit or Restricted Stock Award, Requisite Service Period Recognition</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="AllocatedShareBasedCompensationExpense" xlink:title="AllocatedShareBasedCompensationExpense" />
    <link:label xlink:type="resource" xlink:label="label_AllocatedShareBasedCompensationExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_AllocatedShareBasedCompensationExpense" xml:lang="en-US" id="label_AllocatedShareBasedCompensationExpense">Total</link:label>
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    <link:label xlink:type="resource" xlink:label="label_AllocatedShareBasedCompensationExpense_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AllocatedShareBasedCompensationExpense" xml:lang="en-US" id="label_AllocatedShareBasedCompensationExpense_2">Allocated Share-based Compensation Expense</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AllocatedShareBasedCompensationExpense" xlink:to="label_AllocatedShareBasedCompensationExpense_2" xlink:title="label: AllocatedShareBasedCompensationExpense to label_AllocatedShareBasedCompensationExpense" use="optional" />
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:label="AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:title="AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" />
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    <link:label xlink:type="resource" xlink:label="label_AssetsCurrentAbstract_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AssetsCurrentAbstract" xml:lang="en-US" id="label_AssetsCurrentAbstract_2">Assets, Current [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AssetsCurrentAbstract" xlink:to="label_AssetsCurrentAbstract_2" xlink:title="label: AssetsCurrentAbstract to label_AssetsCurrentAbstract" use="optional" />
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AssetsAbstract" xlink:label="AssetsAbstract" xlink:title="AssetsAbstract" />
    <link:label xlink:type="resource" xlink:label="label_AssetsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_AssetsAbstract" xml:lang="en-US" id="label_AssetsAbstract">Assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AssetsAbstract" xlink:to="label_AssetsAbstract" xlink:title="label: AssetsAbstract to label_AssetsAbstract" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_AssetsAbstract_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AssetsAbstract" xml:lang="en-US" id="label_AssetsAbstract_2">Assets [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="AssetsAbstract" xlink:to="label_AssetsAbstract_2" xlink:title="label: AssetsAbstract to label_AssetsAbstract" use="optional" />
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    <link:label xlink:type="resource" xlink:label="label_AssetsCurrent" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:title="label_AssetsCurrent" xml:lang="en-US" id="label_AssetsCurrent">Total current assets</link:label>
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    <link:label xlink:type="resource" xlink:label="label_AssetsCurrent_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_AssetsCurrent" xml:lang="en-US" id="label_AssetsCurrent_2">Assets, Current</link:label>
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    <link:label xlink:type="resource" xlink:label="label_BasisOfAccountingPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_BasisOfAccountingPolicyPolicyTextBlock" xml:lang="en-US" id="label_BasisOfAccountingPolicyPolicyTextBlock">Basis of Presentation</link:label>
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    <link:label xlink:type="resource" xlink:label="label_BasisOfAccountingPolicyPolicyTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_BasisOfAccountingPolicyPolicyTextBlock" xml:lang="en-US" id="label_BasisOfAccountingPolicyPolicyTextBlock_2">Basis of Accounting, Policy [Policy Text Block]</link:label>
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    <link:label xlink:type="resource" xlink:label="label_CashAndCashEquivalentsAtCarryingValue_5" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_CashAndCashEquivalentsAtCarryingValue" xml:lang="en-US" id="label_CashAndCashEquivalentsAtCarryingValue_5">Cash and Cash Equivalents, at Carrying Value</link:label>
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    <link:label xlink:type="resource" xlink:label="label_CashAndCashEquivalentsAtCarryingValue_6" xlink:role="http://www.xbrl.org/2003/role/positiveTerseLabel" xlink:title="label_CashAndCashEquivalentsAtCarryingValue" xml:lang="en-US" id="label_CashAndCashEquivalentsAtCarryingValue_6">Cash and Cash Equivalents</link:label>
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    <link:label xlink:type="resource" xlink:label="label_CashAndCashEquivalentsAtCarryingValue_7" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_CashAndCashEquivalentsAtCarryingValue" xml:lang="en-US" id="label_CashAndCashEquivalentsAtCarryingValue_7">Cash and cash equivalents</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="CashAndCashEquivalentsAtCarryingValue" xlink:to="label_CashAndCashEquivalentsAtCarryingValue_7" xlink:title="label: CashAndCashEquivalentsAtCarryingValue to label_CashAndCashEquivalentsAtCarryingValue" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CashAndCashEquivalentsPolicyTextBlock" xlink:label="CashAndCashEquivalentsPolicyTextBlock" xlink:title="CashAndCashEquivalentsPolicyTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_CashAndCashEquivalentsPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_CashAndCashEquivalentsPolicyTextBlock" xml:lang="en-US" id="label_CashAndCashEquivalentsPolicyTextBlock">Cash and Cash Equivalents</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure" xlink:label="CashAndCashEquivalentsFairValueDisclosure" xlink:title="CashAndCashEquivalentsFairValueDisclosure" />
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    <link:label xlink:type="resource" xlink:label="label_CommitmentsAndContingenciesDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_CommitmentsAndContingenciesDisclosureAbstract" xml:lang="en-US" id="label_CommitmentsAndContingenciesDisclosureAbstract">Commitments and Contingencies.</link:label>
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    <link:label xlink:type="resource" xlink:label="label_CommitmentsAndContingencies_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_CommitmentsAndContingencies" xml:lang="en-US" id="label_CommitmentsAndContingencies_2">Commitments and Contingencies</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:label="CommitmentsAndContingenciesDisclosureTextBlock" xlink:title="CommitmentsAndContingenciesDisclosureTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_CommitmentsAndContingenciesDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_CommitmentsAndContingenciesDisclosureTextBlock" xml:lang="en-US" id="label_CommitmentsAndContingenciesDisclosureTextBlock">Commitments and Contingencies</link:label>
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    <link:label xlink:type="resource" xlink:label="label_CommitmentsAndContingenciesDisclosureTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_CommitmentsAndContingenciesDisclosureTextBlock" xml:lang="en-US" id="label_CommitmentsAndContingenciesDisclosureTextBlock_2">Commitments and Contingencies Disclosure [Text Block]</link:label>
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    <link:label xlink:type="resource" xlink:label="label_CommonStockParOrStatedValuePerShare_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_CommonStockParOrStatedValuePerShare" xml:lang="en-US" id="label_CommonStockParOrStatedValuePerShare_2">Common Stock, Par or Stated Value Per Share</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockMember" xlink:label="CommonStockMember" xlink:title="CommonStockMember" />
    <link:label xlink:type="resource" xlink:label="label_CommonStockMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_CommonStockMember" xml:lang="en-US" id="label_CommonStockMember">Common Stock [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="CommonStockMember" xlink:to="label_CommonStockMember" xlink:title="label: CommonStockMember to label_CommonStockMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_CommonStockMember_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_CommonStockMember" xml:lang="en-US" id="label_CommonStockMember_2">Common Shares</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="CommonStockMember" xlink:to="label_CommonStockMember_2" xlink:title="label: CommonStockMember to label_CommonStockMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_CommonStockMember_3" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_CommonStockMember" xml:lang="en-US" id="label_CommonStockMember_3">Common Stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="CommonStockMember" xlink:to="label_CommonStockMember_3" xlink:title="label: CommonStockMember to label_CommonStockMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockValue" xlink:label="CommonStockValue" xlink:title="CommonStockValue" />
    <link:label xlink:type="resource" xlink:label="label_CommonStockValue" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_CommonStockValue" xml:lang="en-US" id="label_CommonStockValue">Common stock, $0.0001 par value; 100,000,000 shares authorized; 29,720,422 and 29,587,258 shares issued and outstanding at June 30, 2014 and December 31, 2013, respectively</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="CommonStockValue" xlink:to="label_CommonStockValue" xlink:title="label: CommonStockValue to label_CommonStockValue" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_CommonStockValue_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_CommonStockValue" xml:lang="en-US" id="label_CommonStockValue_2">Common Stock, Value, Issued</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="CommonStockValue" xlink:to="label_CommonStockValue_2" xlink:title="label: CommonStockValue to label_CommonStockValue" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockSharesIssued" xlink:label="CommonStockSharesIssued" xlink:title="CommonStockSharesIssued" />
    <link:label xlink:type="resource" xlink:label="label_CommonStockSharesIssued" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_CommonStockSharesIssued" xml:lang="en-US" id="label_CommonStockSharesIssued">Common stock, shares issued</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="CommonStockSharesIssued" xlink:to="label_CommonStockSharesIssued" xlink:title="label: CommonStockSharesIssued to label_CommonStockSharesIssued" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_CommonStockSharesIssued_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_CommonStockSharesIssued" xml:lang="en-US" id="label_CommonStockSharesIssued_2">Common Stock, Shares, Issued</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="CommonStockSharesIssued" xlink:to="label_CommonStockSharesIssued_2" xlink:title="label: CommonStockSharesIssued to label_CommonStockSharesIssued" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="CommonStockSharesAuthorized" xlink:title="CommonStockSharesAuthorized" />
    <link:label xlink:type="resource" xlink:label="label_CommonStockSharesAuthorized" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_CommonStockSharesAuthorized" xml:lang="en-US" id="label_CommonStockSharesAuthorized">Common stock, shares authorized</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="CommonStockSharesAuthorized" xlink:to="label_CommonStockSharesAuthorized" xlink:title="label: CommonStockSharesAuthorized to label_CommonStockSharesAuthorized" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_CommonStockSharesAuthorized_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_CommonStockSharesAuthorized" xml:lang="en-US" id="label_CommonStockSharesAuthorized_2">Common Stock, Shares Authorized</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="CommonStockSharesAuthorized" xlink:to="label_CommonStockSharesAuthorized_2" xlink:title="label: CommonStockSharesAuthorized to label_CommonStockSharesAuthorized" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="CommonStockSharesOutstanding" xlink:title="CommonStockSharesOutstanding" />
    <link:label xlink:type="resource" xlink:label="label_CommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_CommonStockSharesOutstanding" xml:lang="en-US" id="label_CommonStockSharesOutstanding">Common stock, shares outstanding</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="CommonStockSharesOutstanding" xlink:to="label_CommonStockSharesOutstanding" xlink:title="label: CommonStockSharesOutstanding to label_CommonStockSharesOutstanding" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_CommonStockSharesOutstanding_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_CommonStockSharesOutstanding" xml:lang="en-US" id="label_CommonStockSharesOutstanding_2">Common Stock, Shares, Outstanding</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="CommonStockSharesOutstanding" xlink:to="label_CommonStockSharesOutstanding_2" xlink:title="label: CommonStockSharesOutstanding to label_CommonStockSharesOutstanding" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ComponentsOfDeferredTaxAssetsAbstract" xlink:label="ComponentsOfDeferredTaxAssetsAbstract" xlink:title="ComponentsOfDeferredTaxAssetsAbstract" />
    <link:label xlink:type="resource" xlink:label="label_ComponentsOfDeferredTaxAssetsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ComponentsOfDeferredTaxAssetsAbstract" xml:lang="en-US" id="label_ComponentsOfDeferredTaxAssetsAbstract">Significant components of the Company's deferred tax assets</link:label>
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    <link:label xlink:type="resource" xlink:label="label_ComponentsOfDeferredTaxAssetsAbstract_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ComponentsOfDeferredTaxAssetsAbstract" xml:lang="en-US" id="label_ComponentsOfDeferredTaxAssetsAbstract_2">Components of Deferred Tax Assets [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ComponentsOfDeferredTaxAssetsAbstract" xlink:to="label_ComponentsOfDeferredTaxAssetsAbstract_2" xlink:title="label: ComponentsOfDeferredTaxAssetsAbstract to label_ComponentsOfDeferredTaxAssetsAbstract" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ComponentsOfIncomeTaxExpenseBenefitContinuingOperationsAbstract" xlink:label="ComponentsOfIncomeTaxExpenseBenefitContinuingOperationsAbstract" xlink:title="ComponentsOfIncomeTaxExpenseBenefitContinuingOperationsAbstract" />
    <link:label xlink:type="resource" xlink:label="label_ComponentsOfIncomeTaxExpenseBenefitContinuingOperationsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ComponentsOfIncomeTaxExpenseBenefitContinuingOperationsAbstract" xml:lang="en-US" id="label_ComponentsOfIncomeTaxExpenseBenefitContinuingOperationsAbstract">Components of income (loss) before income taxes</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ComprehensiveIncomePolicyPolicyTextBlock" xlink:label="ComprehensiveIncomePolicyPolicyTextBlock" xlink:title="ComprehensiveIncomePolicyPolicyTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_ComprehensiveIncomePolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ComprehensiveIncomePolicyPolicyTextBlock" xml:lang="en-US" id="label_ComprehensiveIncomePolicyPolicyTextBlock">Comprehensive Income, Policy [Policy Text Block]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ComprehensiveIncomePolicyPolicyTextBlock" xlink:to="label_ComprehensiveIncomePolicyPolicyTextBlock" xlink:title="label: ComprehensiveIncomePolicyPolicyTextBlock to label_ComprehensiveIncomePolicyPolicyTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ComprehensiveIncomePolicyPolicyTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ComprehensiveIncomePolicyPolicyTextBlock" xml:lang="en-US" id="label_ComprehensiveIncomePolicyPolicyTextBlock_2">Comprehensive Loss</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ComprehensiveIncomePolicyPolicyTextBlock" xlink:to="label_ComprehensiveIncomePolicyPolicyTextBlock_2" xlink:title="label: ComprehensiveIncomePolicyPolicyTextBlock to label_ComprehensiveIncomePolicyPolicyTextBlock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="ComprehensiveIncomeNetOfTax" xlink:title="ComprehensiveIncomeNetOfTax" />
    <link:label xlink:type="resource" xlink:label="label_ComprehensiveIncomeNetOfTax" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ComprehensiveIncomeNetOfTax" xml:lang="en-US" id="label_ComprehensiveIncomeNetOfTax">Comprehensive loss</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ComprehensiveIncomeNetOfTax" xlink:to="label_ComprehensiveIncomeNetOfTax" xlink:title="label: ComprehensiveIncomeNetOfTax to label_ComprehensiveIncomeNetOfTax" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ComprehensiveIncomeNetOfTax_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ComprehensiveIncomeNetOfTax" xml:lang="en-US" id="label_ComprehensiveIncomeNetOfTax_2">Comprehensive Income (Loss), Net of Tax, Attributable to Parent</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ComprehensiveIncomeNetOfTax" xlink:to="label_ComprehensiveIncomeNetOfTax_2" xlink:title="label: ComprehensiveIncomeNetOfTax to label_ComprehensiveIncomeNetOfTax" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConsolidationPolicyTextBlock" xlink:label="ConsolidationPolicyTextBlock" xlink:title="ConsolidationPolicyTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_ConsolidationPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ConsolidationPolicyTextBlock" xml:lang="en-US" id="label_ConsolidationPolicyTextBlock">Basis of Consolidation</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ConsolidationPolicyTextBlock" xlink:to="label_ConsolidationPolicyTextBlock" xlink:title="label: ConsolidationPolicyTextBlock to label_ConsolidationPolicyTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ConsolidationPolicyTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ConsolidationPolicyTextBlock" xml:lang="en-US" id="label_ConsolidationPolicyTextBlock_2">Consolidation, Policy [Policy Text Block]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ConsolidationPolicyTextBlock" xlink:to="label_ConsolidationPolicyTextBlock_2" xlink:title="label: ConsolidationPolicyTextBlock to label_ConsolidationPolicyTextBlock" use="optional" />
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    <link:label xlink:type="resource" xlink:label="label_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestChangesPurchaseOfInterestByParent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestChangesPurchaseOfInterestByParent" xml:lang="en-US" id="label_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestChangesPurchaseOfInterestByParent">Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Purchase of Interest by Parent</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestChangesPurchaseOfInterestByParent" xlink:to="label_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestChangesPurchaseOfInterestByParent" xlink:title="label: ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestChangesPurchaseOfInterestByParent to label_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestChangesPurchaseOfInterestByParent" use="optional" />
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    <link:label xlink:type="resource" xlink:label="label_ConstructionInProgressMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ConstructionInProgressMember" xml:lang="en-US" id="label_ConstructionInProgressMember">Construction in process</link:label>
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    <link:label xlink:type="resource" xlink:label="label_ConstructionInProgressMember_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ConstructionInProgressMember" xml:lang="en-US" id="label_ConstructionInProgressMember_2">Construction in Progress [Member]</link:label>
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    <link:label xlink:type="resource" xlink:label="label_ConversionOfStockAmountConverted1_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ConversionOfStockAmountConverted1" xml:lang="en-US" id="label_ConversionOfStockAmountConverted1_2">Conversion of convertible preferred stock upon initial public offering</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConvertiblePreferredStockMember" xlink:label="ConvertiblePreferredStockMember" xlink:title="ConvertiblePreferredStockMember" />
    <link:label xlink:type="resource" xlink:label="label_ConvertiblePreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ConvertiblePreferredStockMember" xml:lang="en-US" id="label_ConvertiblePreferredStockMember">Convertible preferred stock</link:label>
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    <link:label xlink:type="resource" xlink:label="label_ConvertiblePreferredStockMember_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ConvertiblePreferredStockMember" xml:lang="en-US" id="label_ConvertiblePreferredStockMember_2">Convertible Preferred Stock [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ConvertiblePreferredStockMember" xlink:to="label_ConvertiblePreferredStockMember_2" xlink:title="label: ConvertiblePreferredStockMember to label_ConvertiblePreferredStockMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtConversionOriginalDebtAmount1" xlink:label="DebtConversionOriginalDebtAmount1" xlink:title="DebtConversionOriginalDebtAmount1" />
    <link:label xlink:type="resource" xlink:label="label_DebtConversionOriginalDebtAmount1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_DebtConversionOriginalDebtAmount1" xml:lang="en-US" id="label_DebtConversionOriginalDebtAmount1">Debt Conversion, Original Debt, Amount</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DebtConversionOriginalDebtAmount1" xlink:to="label_DebtConversionOriginalDebtAmount1" xlink:title="label: DebtConversionOriginalDebtAmount1 to label_DebtConversionOriginalDebtAmount1" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_DebtConversionOriginalDebtAmount1_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_DebtConversionOriginalDebtAmount1" xml:lang="en-US" id="label_DebtConversionOriginalDebtAmount1_2">Amount of convertible notes converted into Series A Preferred Stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DebtConversionOriginalDebtAmount1" xlink:to="label_DebtConversionOriginalDebtAmount1_2" xlink:title="label: DebtConversionOriginalDebtAmount1 to label_DebtConversionOriginalDebtAmount1" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtInstrumentConvertibleBeneficialConversionFeature" xlink:label="DebtInstrumentConvertibleBeneficialConversionFeature" xlink:title="DebtInstrumentConvertibleBeneficialConversionFeature" />
    <link:label xlink:type="resource" xlink:label="label_DebtInstrumentConvertibleBeneficialConversionFeature" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_DebtInstrumentConvertibleBeneficialConversionFeature" xml:lang="en-US" id="label_DebtInstrumentConvertibleBeneficialConversionFeature">Debt Instrument, Convertible, Beneficial Conversion Feature</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DebtInstrumentConvertibleBeneficialConversionFeature" xlink:to="label_DebtInstrumentConvertibleBeneficialConversionFeature" xlink:title="label: DebtInstrumentConvertibleBeneficialConversionFeature to label_DebtInstrumentConvertibleBeneficialConversionFeature" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_DebtInstrumentConvertibleBeneficialConversionFeature_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_DebtInstrumentConvertibleBeneficialConversionFeature" xml:lang="en-US" id="label_DebtInstrumentConvertibleBeneficialConversionFeature_2">Beneficial conversion feature</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DebtInstrumentConvertibleBeneficialConversionFeature" xlink:to="label_DebtInstrumentConvertibleBeneficialConversionFeature_2" xlink:title="label: DebtInstrumentConvertibleBeneficialConversionFeature to label_DebtInstrumentConvertibleBeneficialConversionFeature" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtConversionConvertedInstrumentAmount1" xlink:label="DebtConversionConvertedInstrumentAmount1" xlink:title="DebtConversionConvertedInstrumentAmount1" />
    <link:label xlink:type="resource" xlink:label="label_DebtConversionConvertedInstrumentAmount1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_DebtConversionConvertedInstrumentAmount1" xml:lang="en-US" id="label_DebtConversionConvertedInstrumentAmount1">Conversion of notes payable to preferred stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DebtConversionConvertedInstrumentAmount1" xlink:to="label_DebtConversionConvertedInstrumentAmount1" xlink:title="label: DebtConversionConvertedInstrumentAmount1 to label_DebtConversionConvertedInstrumentAmount1" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_DebtConversionConvertedInstrumentAmount1_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_DebtConversionConvertedInstrumentAmount1" xml:lang="en-US" id="label_DebtConversionConvertedInstrumentAmount1_2">Debt Conversion, Converted Instrument, Amount</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DebtConversionConvertedInstrumentAmount1" xlink:to="label_DebtConversionConvertedInstrumentAmount1_2" xlink:title="label: DebtConversionConvertedInstrumentAmount1 to label_DebtConversionConvertedInstrumentAmount1" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredTaxExpenseFromStockOptionsExercised" xlink:label="DeferredTaxExpenseFromStockOptionsExercised" xlink:title="DeferredTaxExpenseFromStockOptionsExercised" />
    <link:label xlink:type="resource" xlink:label="label_DeferredTaxExpenseFromStockOptionsExercised" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_DeferredTaxExpenseFromStockOptionsExercised" xml:lang="en-US" id="label_DeferredTaxExpenseFromStockOptionsExercised">Deduction for option exercises</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DeferredTaxExpenseFromStockOptionsExercised" xlink:to="label_DeferredTaxExpenseFromStockOptionsExercised" xlink:title="label: DeferredTaxExpenseFromStockOptionsExercised to label_DeferredTaxExpenseFromStockOptionsExercised" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_DeferredTaxExpenseFromStockOptionsExercised_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_DeferredTaxExpenseFromStockOptionsExercised" xml:lang="en-US" id="label_DeferredTaxExpenseFromStockOptionsExercised_2">Deferred Tax Expense from Stock Options Exercised</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DeferredTaxExpenseFromStockOptionsExercised" xlink:to="label_DeferredTaxExpenseFromStockOptionsExercised_2" xlink:title="label: DeferredTaxExpenseFromStockOptionsExercised to label_DeferredTaxExpenseFromStockOptionsExercised" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredRentCreditNoncurrent" xlink:label="DeferredRentCreditNoncurrent" xlink:title="DeferredRentCreditNoncurrent" />
    <link:label xlink:type="resource" xlink:label="label_DeferredRentCreditNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_DeferredRentCreditNoncurrent" xml:lang="en-US" id="label_DeferredRentCreditNoncurrent">Deferred Rent Credit, Noncurrent</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DeferredRentCreditNoncurrent" xlink:to="label_DeferredRentCreditNoncurrent" xlink:title="label: DeferredRentCreditNoncurrent to label_DeferredRentCreditNoncurrent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_DeferredRentCreditNoncurrent_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_DeferredRentCreditNoncurrent" xml:lang="en-US" id="label_DeferredRentCreditNoncurrent_2">Deferred rent</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DeferredRentCreditNoncurrent" xlink:to="label_DeferredRentCreditNoncurrent_2" xlink:title="label: DeferredRentCreditNoncurrent to label_DeferredRentCreditNoncurrent" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredRevenueCurrent" xlink:label="DeferredRevenueCurrent" xlink:title="DeferredRevenueCurrent" />
    <link:label xlink:type="resource" xlink:label="label_DeferredRevenueCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_DeferredRevenueCurrent" xml:lang="en-US" id="label_DeferredRevenueCurrent">Deferred Revenue, Current</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DeferredRevenueCurrent" xlink:to="label_DeferredRevenueCurrent" xlink:title="label: DeferredRevenueCurrent to label_DeferredRevenueCurrent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_DeferredRevenueCurrent_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_DeferredRevenueCurrent" xml:lang="en-US" id="label_DeferredRevenueCurrent_2">Deferred revenue</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DeferredRevenueCurrent" xlink:to="label_DeferredRevenueCurrent_2" xlink:title="label: DeferredRevenueCurrent to label_DeferredRevenueCurrent" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredRentCreditCurrent" xlink:label="DeferredRentCreditCurrent" xlink:title="DeferredRentCreditCurrent" />
    <link:label xlink:type="resource" xlink:label="label_DeferredRentCreditCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_DeferredRentCreditCurrent" xml:lang="en-US" id="label_DeferredRentCreditCurrent">Deferred Rent Credit, Current</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DeferredRentCreditCurrent" xlink:to="label_DeferredRentCreditCurrent" xlink:title="label: DeferredRentCreditCurrent to label_DeferredRentCreditCurrent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_DeferredRentCreditCurrent_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_DeferredRentCreditCurrent" xml:lang="en-US" id="label_DeferredRentCreditCurrent_2">Deferred rent</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DeferredRentCreditCurrent" xlink:to="label_DeferredRentCreditCurrent_2" xlink:title="label: DeferredRentCreditCurrent to label_DeferredRentCreditCurrent" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredTaxAssetsGross" xlink:label="DeferredTaxAssetsGross" xlink:title="DeferredTaxAssetsGross" />
    <link:label xlink:type="resource" xlink:label="label_DeferredTaxAssetsGross" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:title="label_DeferredTaxAssetsGross" xml:lang="en-US" id="label_DeferredTaxAssetsGross">Total deferred tax assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DeferredTaxAssetsGross" xlink:to="label_DeferredTaxAssetsGross" xlink:title="label: DeferredTaxAssetsGross to label_DeferredTaxAssetsGross" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_DeferredTaxAssetsGross_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_DeferredTaxAssetsGross" xml:lang="en-US" id="label_DeferredTaxAssetsGross_2">Deferred Tax Assets, Gross</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DeferredTaxAssetsGross" xlink:to="label_DeferredTaxAssetsGross_2" xlink:title="label: DeferredTaxAssetsGross to label_DeferredTaxAssetsGross" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsResearch" xlink:label="DeferredTaxAssetsTaxCreditCarryforwardsResearch" xlink:title="DeferredTaxAssetsTaxCreditCarryforwardsResearch" />
    <link:label xlink:type="resource" xlink:label="label_DeferredTaxAssetsTaxCreditCarryforwardsResearch" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_DeferredTaxAssetsTaxCreditCarryforwardsResearch" xml:lang="en-US" id="label_DeferredTaxAssetsTaxCreditCarryforwardsResearch">Research and development credits</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DeferredTaxAssetsTaxCreditCarryforwardsResearch" xlink:to="label_DeferredTaxAssetsTaxCreditCarryforwardsResearch" xlink:title="label: DeferredTaxAssetsTaxCreditCarryforwardsResearch to label_DeferredTaxAssetsTaxCreditCarryforwardsResearch" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_DeferredTaxAssetsTaxCreditCarryforwardsResearch_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_DeferredTaxAssetsTaxCreditCarryforwardsResearch" xml:lang="en-US" id="label_DeferredTaxAssetsTaxCreditCarryforwardsResearch_2">Deferred Tax Assets, Tax Credit Carryforwards, Research</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DeferredTaxAssetsTaxCreditCarryforwardsResearch" xlink:to="label_DeferredTaxAssetsTaxCreditCarryforwardsResearch_2" xlink:title="label: DeferredTaxAssetsTaxCreditCarryforwardsResearch to label_DeferredTaxAssetsTaxCreditCarryforwardsResearch" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredTaxAssetsNetAbstract" xlink:label="DeferredTaxAssetsNetAbstract" xlink:title="DeferredTaxAssetsNetAbstract" />
    <link:label xlink:type="resource" xlink:label="label_DeferredTaxAssetsNetAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_DeferredTaxAssetsNetAbstract" xml:lang="en-US" id="label_DeferredTaxAssetsNetAbstract">Deferred tax assets:</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DeferredTaxAssetsNetAbstract" xlink:to="label_DeferredTaxAssetsNetAbstract" xlink:title="label: DeferredTaxAssetsNetAbstract to label_DeferredTaxAssetsNetAbstract" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_DeferredTaxAssetsNetAbstract_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_DeferredTaxAssetsNetAbstract" xml:lang="en-US" id="label_DeferredTaxAssetsNetAbstract_2">Deferred Tax Assets, Net [Abstract]</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsForeign" xlink:label="DeferredTaxAssetsOperatingLossCarryforwardsForeign" xlink:title="DeferredTaxAssetsOperatingLossCarryforwardsForeign" />
    <link:label xlink:type="resource" xlink:label="label_DeferredTaxAssetsOperatingLossCarryforwardsForeign" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_DeferredTaxAssetsOperatingLossCarryforwardsForeign" xml:lang="en-US" id="label_DeferredTaxAssetsOperatingLossCarryforwardsForeign">Foreign net operating loss carryforwards</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DeferredTaxAssetsOperatingLossCarryforwardsForeign" xlink:to="label_DeferredTaxAssetsOperatingLossCarryforwardsForeign" xlink:title="label: DeferredTaxAssetsOperatingLossCarryforwardsForeign to label_DeferredTaxAssetsOperatingLossCarryforwardsForeign" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_DeferredTaxAssetsOperatingLossCarryforwardsForeign_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_DeferredTaxAssetsOperatingLossCarryforwardsForeign" xml:lang="en-US" id="label_DeferredTaxAssetsOperatingLossCarryforwardsForeign_2">Deferred Tax Assets, Operating Loss Carryforwards, Foreign</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DeferredTaxAssetsOperatingLossCarryforwardsForeign" xlink:to="label_DeferredTaxAssetsOperatingLossCarryforwardsForeign_2" xlink:title="label: DeferredTaxAssetsOperatingLossCarryforwardsForeign to label_DeferredTaxAssetsOperatingLossCarryforwardsForeign" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredTaxAssetsValuationAllowance" xlink:label="DeferredTaxAssetsValuationAllowance" xlink:title="DeferredTaxAssetsValuationAllowance" />
    <link:label xlink:type="resource" xlink:label="label_DeferredTaxAssetsValuationAllowance" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:title="label_DeferredTaxAssetsValuationAllowance" xml:lang="en-US" id="label_DeferredTaxAssetsValuationAllowance">Less valuation allowance</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DeferredTaxAssetsValuationAllowance" xlink:to="label_DeferredTaxAssetsValuationAllowance" xlink:title="label: DeferredTaxAssetsValuationAllowance to label_DeferredTaxAssetsValuationAllowance" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_DeferredTaxAssetsValuationAllowance_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_DeferredTaxAssetsValuationAllowance" xml:lang="en-US" id="label_DeferredTaxAssetsValuationAllowance_2">Deferred Tax Assets, Valuation Allowance</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DeferredTaxAssetsValuationAllowance" xlink:to="label_DeferredTaxAssetsValuationAllowance_2" xlink:title="label: DeferredTaxAssetsValuationAllowance to label_DeferredTaxAssetsValuationAllowance" use="optional" />
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    <link:label xlink:type="resource" xlink:label="label_Depreciation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_Depreciation" xml:lang="en-US" id="label_Depreciation">Depreciation and amortization expense</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="Depreciation" xlink:to="label_Depreciation" xlink:title="label: Depreciation to label_Depreciation" use="optional" />
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    <link:label xlink:type="resource" xlink:label="label_DepreciationAndAmortization" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_DepreciationAndAmortization" xml:lang="en-US" id="label_DepreciationAndAmortization">Depreciation and amortization</link:label>
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    <link:label xlink:type="resource" xlink:label="label_DepreciationAndAmortization_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_DepreciationAndAmortization" xml:lang="en-US" id="label_DepreciationAndAmortization_2">Depreciation, Depletion and Amortization, Nonproduction</link:label>
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    <link:label xlink:type="resource" xlink:label="label_DerivativeNumberOfInstrumentsHeld" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_DerivativeNumberOfInstrumentsHeld" xml:lang="en-US" id="label_DerivativeNumberOfInstrumentsHeld">Number of freestanding derivative instruments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DerivativeNumberOfInstrumentsHeld" xlink:to="label_DerivativeNumberOfInstrumentsHeld" xlink:title="label: DerivativeNumberOfInstrumentsHeld to label_DerivativeNumberOfInstrumentsHeld" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_DerivativeNumberOfInstrumentsHeld_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_DerivativeNumberOfInstrumentsHeld" xml:lang="en-US" id="label_DerivativeNumberOfInstrumentsHeld_2">Derivative, Number of Instruments Held</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DerivativeNumberOfInstrumentsHeld" xlink:to="label_DerivativeNumberOfInstrumentsHeld_2" xlink:title="label: DerivativeNumberOfInstrumentsHeld to label_DerivativeNumberOfInstrumentsHeld" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DevelopmentStageEnterpriseDeficitAccumulatedDuringDevelopmentStage" xlink:label="DevelopmentStageEnterpriseDeficitAccumulatedDuringDevelopmentStage" xlink:title="DevelopmentStageEnterpriseDeficitAccumulatedDuringDevelopmentStage" />
    <link:label xlink:type="resource" xlink:label="label_DevelopmentStageEnterpriseDeficitAccumulatedDuringDevelopmentStage" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:title="label_DevelopmentStageEnterpriseDeficitAccumulatedDuringDevelopmentStage" xml:lang="en-US" id="label_DevelopmentStageEnterpriseDeficitAccumulatedDuringDevelopmentStage">Accumulated deficit</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DevelopmentStageEnterpriseDeficitAccumulatedDuringDevelopmentStage" xlink:to="label_DevelopmentStageEnterpriseDeficitAccumulatedDuringDevelopmentStage" xlink:title="label: DevelopmentStageEnterpriseDeficitAccumulatedDuringDevelopmentStage to label_DevelopmentStageEnterpriseDeficitAccumulatedDuringDevelopmentStage" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_DevelopmentStageEnterpriseDeficitAccumulatedDuringDevelopmentStage_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_DevelopmentStageEnterpriseDeficitAccumulatedDuringDevelopmentStage" xml:lang="en-US" id="label_DevelopmentStageEnterpriseDeficitAccumulatedDuringDevelopmentStage_2">Development Stage Enterprise, Deficit Accumulated During Development Stage</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DevelopmentStageEnterpriseDeficitAccumulatedDuringDevelopmentStage" xlink:to="label_DevelopmentStageEnterpriseDeficitAccumulatedDuringDevelopmentStage_2" xlink:title="label: DevelopmentStageEnterpriseDeficitAccumulatedDuringDevelopmentStage to label_DevelopmentStageEnterpriseDeficitAccumulatedDuringDevelopmentStage" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_DevelopmentStageEnterpriseDeficitAccumulatedDuringDevelopmentStage_3" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_DevelopmentStageEnterpriseDeficitAccumulatedDuringDevelopmentStage" xml:lang="en-US" id="label_DevelopmentStageEnterpriseDeficitAccumulatedDuringDevelopmentStage_3">Accumulated deficit since inception</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:label="DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:title="DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xml:lang="en-US" id="label_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock">Stock-based Compensation</link:label>
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    <link:label xlink:type="resource" xlink:label="label_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xml:lang="en-US" id="label_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_2">Disclosure of Compensation Related Costs, Share-based Payments [Text Block]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:to="label_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_2" xlink:title="label: DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock to label_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" use="optional" />
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    <link:label xlink:type="resource" xlink:label="label_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xml:lang="en-US" id="label_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract">Stock-based Compensation</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="label_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:title="label: DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract to label_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DueToRelatedPartiesCurrent" xlink:label="DueToRelatedPartiesCurrent" xlink:title="DueToRelatedPartiesCurrent" />
    <link:label xlink:type="resource" xlink:label="label_DueToRelatedPartiesCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_DueToRelatedPartiesCurrent" xml:lang="en-US" id="label_DueToRelatedPartiesCurrent">Accounts payable or accrued expenses</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DueToRelatedPartiesCurrent" xlink:to="label_DueToRelatedPartiesCurrent" xlink:title="label: DueToRelatedPartiesCurrent to label_DueToRelatedPartiesCurrent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_DueToRelatedPartiesCurrent_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_DueToRelatedPartiesCurrent" xml:lang="en-US" id="label_DueToRelatedPartiesCurrent_2">Due to Related Parties, Current</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="DueToRelatedPartiesCurrent" xlink:to="label_DueToRelatedPartiesCurrent_2" xlink:title="label: DueToRelatedPartiesCurrent to label_DueToRelatedPartiesCurrent" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EarningsPerShareBasicAndDiluted" xlink:label="EarningsPerShareBasicAndDiluted" xlink:title="EarningsPerShareBasicAndDiluted" />
    <link:label xlink:type="resource" xlink:label="label_EarningsPerShareBasicAndDiluted" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_EarningsPerShareBasicAndDiluted" xml:lang="en-US" id="label_EarningsPerShareBasicAndDiluted">Net loss per share applicable to common stockholders-basic and diluted (in dollars per share)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EarningsPerShareBasicAndDiluted" xlink:to="label_EarningsPerShareBasicAndDiluted" xlink:title="label: EarningsPerShareBasicAndDiluted to label_EarningsPerShareBasicAndDiluted" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_EarningsPerShareBasicAndDiluted_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_EarningsPerShareBasicAndDiluted" xml:lang="en-US" id="label_EarningsPerShareBasicAndDiluted_2">Earnings Per Share, Basic and Diluted</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EarningsPerShareBasicAndDiluted" xlink:to="label_EarningsPerShareBasicAndDiluted_2" xlink:title="label: EarningsPerShareBasicAndDiluted to label_EarningsPerShareBasicAndDiluted" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_EarningsPerShareBasicAndDiluted_3" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_EarningsPerShareBasicAndDiluted" xml:lang="en-US" id="label_EarningsPerShareBasicAndDiluted_3">Net loss per share applicable to common stockholders basic and diluted (in dollars per share)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EarningsPerShareBasicAndDiluted" xlink:to="label_EarningsPerShareBasicAndDiluted_3" xlink:title="label: EarningsPerShareBasicAndDiluted to label_EarningsPerShareBasicAndDiluted" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EarningsPerShareTextBlock" xlink:label="EarningsPerShareTextBlock" xlink:title="EarningsPerShareTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_EarningsPerShareTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_EarningsPerShareTextBlock" xml:lang="en-US" id="label_EarningsPerShareTextBlock">Net Loss Per Share</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EarningsPerShareTextBlock" xlink:to="label_EarningsPerShareTextBlock" xlink:title="label: EarningsPerShareTextBlock to label_EarningsPerShareTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_EarningsPerShareTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_EarningsPerShareTextBlock" xml:lang="en-US" id="label_EarningsPerShareTextBlock_2">Earnings Per Share [Text Block]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EarningsPerShareTextBlock" xlink:to="label_EarningsPerShareTextBlock_2" xlink:title="label: EarningsPerShareTextBlock to label_EarningsPerShareTextBlock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EarningsPerSharePolicyTextBlock" xlink:label="EarningsPerSharePolicyTextBlock" xlink:title="EarningsPerSharePolicyTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_EarningsPerSharePolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_EarningsPerSharePolicyTextBlock" xml:lang="en-US" id="label_EarningsPerSharePolicyTextBlock">Net Loss Per Share</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EarningsPerSharePolicyTextBlock" xlink:to="label_EarningsPerSharePolicyTextBlock" xlink:title="label: EarningsPerSharePolicyTextBlock to label_EarningsPerSharePolicyTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_EarningsPerSharePolicyTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_EarningsPerSharePolicyTextBlock" xml:lang="en-US" id="label_EarningsPerSharePolicyTextBlock_2">Earnings Per Share, Policy [Policy Text Block]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EarningsPerSharePolicyTextBlock" xlink:to="label_EarningsPerSharePolicyTextBlock_2" xlink:title="label: EarningsPerSharePolicyTextBlock to label_EarningsPerSharePolicyTextBlock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="EarningsPerShareAbstract" xlink:title="EarningsPerShareAbstract" />
    <link:label xlink:type="resource" xlink:label="label_EarningsPerShareAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_EarningsPerShareAbstract" xml:lang="en-US" id="label_EarningsPerShareAbstract">Net Loss Per Share</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:label="EffectiveIncomeTaxRateContinuingOperations" xlink:title="EffectiveIncomeTaxRateContinuingOperations" />
    <link:label xlink:type="resource" xlink:label="label_EffectiveIncomeTaxRateContinuingOperations" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:title="label_EffectiveIncomeTaxRateContinuingOperations" xml:lang="en-US" id="label_EffectiveIncomeTaxRateContinuingOperations">Effective income tax rate (as a percent)</link:label>
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    <link:label xlink:type="resource" xlink:label="label_EffectiveIncomeTaxRateContinuingOperations_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_EffectiveIncomeTaxRateContinuingOperations" xml:lang="en-US" id="label_EffectiveIncomeTaxRateContinuingOperations_2">Effective Income Tax Rate Reconciliation, Percent</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:label="EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:title="EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" />
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:label="EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:title="EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" />
    <link:label xlink:type="resource" xlink:label="label_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xml:lang="en-US" id="label_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate">Federal income tax expense at statutory rate (as a percent)</link:label>
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:to="label_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_2" xlink:title="label: EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate to label_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsResearch" xlink:label="EffectiveIncomeTaxRateReconciliationTaxCreditsResearch" xlink:title="EffectiveIncomeTaxRateReconciliationTaxCreditsResearch" />
    <link:label xlink:type="resource" xlink:label="label_EffectiveIncomeTaxRateReconciliationTaxCreditsResearch" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:title="label_EffectiveIncomeTaxRateReconciliationTaxCreditsResearch" xml:lang="en-US" id="label_EffectiveIncomeTaxRateReconciliationTaxCreditsResearch">Research and development credit (as a percent)</link:label>
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EffectiveIncomeTaxRateReconciliationTaxCreditsResearch" xlink:to="label_EffectiveIncomeTaxRateReconciliationTaxCreditsResearch_2" xlink:title="label: EffectiveIncomeTaxRateReconciliationTaxCreditsResearch to label_EffectiveIncomeTaxRateReconciliationTaxCreditsResearch" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential" xlink:label="EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential" xlink:title="EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential" />
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential" xlink:to="label_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential_2" xlink:title="label: EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential to label_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:label="EmployeeRelatedLiabilitiesCurrent" xlink:title="EmployeeRelatedLiabilitiesCurrent" />
    <link:label xlink:type="resource" xlink:label="label_EmployeeRelatedLiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_EmployeeRelatedLiabilitiesCurrent" xml:lang="en-US" id="label_EmployeeRelatedLiabilitiesCurrent">Payroll and employee-related costs</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EmployeeRelatedLiabilitiesCurrent" xlink:to="label_EmployeeRelatedLiabilitiesCurrent" xlink:title="label: EmployeeRelatedLiabilitiesCurrent to label_EmployeeRelatedLiabilitiesCurrent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_EmployeeRelatedLiabilitiesCurrent_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_EmployeeRelatedLiabilitiesCurrent" xml:lang="en-US" id="label_EmployeeRelatedLiabilitiesCurrent_2">Employee-related Liabilities, Current</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EmployeeRelatedLiabilitiesCurrent" xlink:to="label_EmployeeRelatedLiabilitiesCurrent_2" xlink:title="label: EmployeeRelatedLiabilitiesCurrent to label_EmployeeRelatedLiabilitiesCurrent" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" xlink:label="EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" xlink:title="EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" />
    <link:label xlink:type="resource" xlink:label="label_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" xml:lang="en-US" id="label_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems">Total stock-based compensation expense recognized in connection with all share-based payment awards</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" xlink:to="label_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" xlink:title="label: EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems to label_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" xml:lang="en-US" id="label_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_2">Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" xlink:to="label_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_2" xlink:title="label: EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems to label_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" xlink:label="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" xlink:title="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" />
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" xlink:to="label_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" xlink:title="label: EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions to label_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" xml:lang="en-US" id="label_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_2">Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" xlink:to="label_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_2" xlink:title="label: EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions to label_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_3" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" xml:lang="en-US" id="label_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_3">Total unrecognized stock-based compensation expense</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" xlink:to="label_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_3" xlink:title="label: EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions to label_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:title="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" />
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:to="label_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_3" xlink:title="label: EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1 to label_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions" xlink:label="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions" xlink:title="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions" />
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    <link:label xlink:type="resource" xlink:label="label_EquipmentMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_EquipmentMember" xml:lang="en-US" id="label_EquipmentMember">Laboratory equipment</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EquipmentMember" xlink:to="label_EquipmentMember" xlink:title="label: EquipmentMember to label_EquipmentMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_EquipmentMember_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_EquipmentMember" xml:lang="en-US" id="label_EquipmentMember_2">Equipment [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="EquipmentMember" xlink:to="label_EquipmentMember_2" xlink:title="label: EquipmentMember to label_EquipmentMember" use="optional" />
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    <link:label xlink:type="resource" xlink:label="label_EstimateOfFairValueFairValueDisclosureMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_EstimateOfFairValueFairValueDisclosureMember" xml:lang="en-US" id="label_EstimateOfFairValueFairValueDisclosureMember">Total</link:label>
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    <link:label xlink:type="resource" xlink:label="label_EstimateOfFairValueFairValueDisclosureMember_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_EstimateOfFairValueFairValueDisclosureMember" xml:lang="en-US" id="label_EstimateOfFairValueFairValueDisclosureMember_2">Estimate of Fair Value Measurement [Member]</link:label>
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    <link:label xlink:type="resource" xlink:label="label_FairValueMeasurementsRecurringMember_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_FairValueMeasurementsRecurringMember" xml:lang="en-US" id="label_FairValueMeasurementsRecurringMember_2">Fair Value, Measurements, Recurring [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="FairValueMeasurementsRecurringMember" xlink:to="label_FairValueMeasurementsRecurringMember_2" xlink:title="label: FairValueMeasurementsRecurringMember to label_FairValueMeasurementsRecurringMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="FairValueMeasurementFrequencyDomain" xlink:title="FairValueMeasurementFrequencyDomain" />
    <link:label xlink:type="resource" xlink:label="label_FairValueMeasurementFrequencyDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_FairValueMeasurementFrequencyDomain" xml:lang="en-US" id="label_FairValueMeasurementFrequencyDomain">Fair Value, Measurement Frequency [Domain]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="FairValueMeasurementFrequencyDomain" xlink:to="label_FairValueMeasurementFrequencyDomain" xlink:title="label: FairValueMeasurementFrequencyDomain to label_FairValueMeasurementFrequencyDomain" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:title="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" />
    <link:label xlink:type="resource" xlink:label="label_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xml:lang="en-US" id="label_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems">Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="label_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:title="label: FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to label_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xml:lang="en-US" id="label_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_2">Fair value of financial instruments</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:label="FairValueDisclosuresAbstract" xlink:title="FairValueDisclosuresAbstract" />
    <link:label xlink:type="resource" xlink:label="label_FairValueDisclosuresAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_FairValueDisclosuresAbstract" xml:lang="en-US" id="label_FairValueDisclosuresAbstract">Fair Value of Financial Instruments</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="FairValueMeasurementsFairValueHierarchyDomain" xlink:title="FairValueMeasurementsFairValueHierarchyDomain" />
    <link:label xlink:type="resource" xlink:label="label_FairValueMeasurementsFairValueHierarchyDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_FairValueMeasurementsFairValueHierarchyDomain" xml:lang="en-US" id="label_FairValueMeasurementsFairValueHierarchyDomain">Fair Value Hierarchy [Domain]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="FairValueMeasurementsFairValueHierarchyDomain" xlink:to="label_FairValueMeasurementsFairValueHierarchyDomain" xlink:title="label: FairValueMeasurementsFairValueHierarchyDomain to label_FairValueMeasurementsFairValueHierarchyDomain" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueOfFinancialInstrumentsPolicy" xlink:label="FairValueOfFinancialInstrumentsPolicy" xlink:title="FairValueOfFinancialInstrumentsPolicy" />
    <link:label xlink:type="resource" xlink:label="label_FairValueOfFinancialInstrumentsPolicy" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_FairValueOfFinancialInstrumentsPolicy" xml:lang="en-US" id="label_FairValueOfFinancialInstrumentsPolicy">Fair Value of Financial Instruments, Policy [Policy Text Block]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="FairValueOfFinancialInstrumentsPolicy" xlink:to="label_FairValueOfFinancialInstrumentsPolicy" xlink:title="label: FairValueOfFinancialInstrumentsPolicy to label_FairValueOfFinancialInstrumentsPolicy" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_FairValueOfFinancialInstrumentsPolicy_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_FairValueOfFinancialInstrumentsPolicy" xml:lang="en-US" id="label_FairValueOfFinancialInstrumentsPolicy_2">Fair Value Measurements</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="FairValueOfFinancialInstrumentsPolicy" xlink:to="label_FairValueOfFinancialInstrumentsPolicy_2" xlink:title="label: FairValueOfFinancialInstrumentsPolicy to label_FairValueOfFinancialInstrumentsPolicy" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueDisclosuresTextBlock" xlink:label="FairValueDisclosuresTextBlock" xlink:title="FairValueDisclosuresTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_FairValueDisclosuresTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_FairValueDisclosuresTextBlock" xml:lang="en-US" id="label_FairValueDisclosuresTextBlock">Fair Value Disclosures [Text Block]</link:label>
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    <link:label xlink:type="resource" xlink:label="label_FairValueDisclosuresTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_FairValueDisclosuresTextBlock" xml:lang="en-US" id="label_FairValueDisclosuresTextBlock_2">Fair Value of Financial Instruments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="FairValueDisclosuresTextBlock" xlink:to="label_FairValueDisclosuresTextBlock_2" xlink:title="label: FairValueDisclosuresTextBlock to label_FairValueDisclosuresTextBlock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueByBalanceSheetGroupingTextBlock" xlink:label="FairValueByBalanceSheetGroupingTextBlock" xlink:title="FairValueByBalanceSheetGroupingTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_FairValueByBalanceSheetGroupingTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_FairValueByBalanceSheetGroupingTextBlock" xml:lang="en-US" id="label_FairValueByBalanceSheetGroupingTextBlock">Schedule of financial assets measured at fair value and indicates the fair value hierarchy of the valuation inputs utilized to determine such fair value</link:label>
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    <link:label xlink:type="resource" xlink:label="label_FairValueByBalanceSheetGroupingTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_FairValueByBalanceSheetGroupingTextBlock" xml:lang="en-US" id="label_FairValueByBalanceSheetGroupingTextBlock_2">Fair Value, by Balance Sheet Grouping [Table Text Block]</link:label>
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    <link:label xlink:type="resource" xlink:label="label_FairValueInputsLevel1Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_FairValueInputsLevel1Member" xml:lang="en-US" id="label_FairValueInputsLevel1Member">Level 1</link:label>
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    <link:label xlink:type="resource" xlink:label="label_FairValueInputsLevel1Member_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_FairValueInputsLevel1Member" xml:lang="en-US" id="label_FairValueInputsLevel1Member_2">Fair Value, Inputs, Level 1 [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="FairValueInputsLevel1Member" xlink:to="label_FairValueInputsLevel1Member_2" xlink:title="label: FairValueInputsLevel1Member to label_FairValueInputsLevel1Member" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_FairValueInputsLevel1Member_3" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_FairValueInputsLevel1Member" xml:lang="en-US" id="label_FairValueInputsLevel1Member_3">Quoted prices in active markets (Level 1)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="FairValueInputsLevel1Member" xlink:to="label_FairValueInputsLevel1Member_3" xlink:title="label: FairValueInputsLevel1Member to label_FairValueInputsLevel1Member" use="optional" />
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    <link:label xlink:type="resource" xlink:label="label_FairValueInputsLevel2Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_FairValueInputsLevel2Member" xml:lang="en-US" id="label_FairValueInputsLevel2Member">Level 2</link:label>
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    <link:label xlink:type="resource" xlink:label="label_FairValueInputsLevel2Member_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_FairValueInputsLevel2Member" xml:lang="en-US" id="label_FairValueInputsLevel2Member_2">Fair Value, Inputs, Level 2 [Member]</link:label>
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    <link:label xlink:type="resource" xlink:label="label_ForeignCountryMember_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ForeignCountryMember" xml:lang="en-US" id="label_ForeignCountryMember_2">Foreign Tax Authority [Member]</link:label>
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    <link:label xlink:type="resource" xlink:label="label_GeneralAndAdministrativeExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_GeneralAndAdministrativeExpense" xml:lang="en-US" id="label_GeneralAndAdministrativeExpense">General and administrative</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="GeneralAndAdministrativeExpense" xlink:to="label_GeneralAndAdministrativeExpense" xlink:title="label: GeneralAndAdministrativeExpense to label_GeneralAndAdministrativeExpense" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_GeneralAndAdministrativeExpense_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_GeneralAndAdministrativeExpense" xml:lang="en-US" id="label_GeneralAndAdministrativeExpense_2">General and Administrative Expense</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_GeneralAndAdministrativeExpenseMember" xlink:label="GeneralAndAdministrativeExpenseMember" xlink:title="GeneralAndAdministrativeExpenseMember" />
    <link:label xlink:type="resource" xlink:label="label_GeneralAndAdministrativeExpenseMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_GeneralAndAdministrativeExpenseMember" xml:lang="en-US" id="label_GeneralAndAdministrativeExpenseMember">General and administrative</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="GeneralAndAdministrativeExpenseMember" xlink:to="label_GeneralAndAdministrativeExpenseMember" xlink:title="label: GeneralAndAdministrativeExpenseMember to label_GeneralAndAdministrativeExpenseMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_GeneralAndAdministrativeExpenseMember_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_GeneralAndAdministrativeExpenseMember" xml:lang="en-US" id="label_GeneralAndAdministrativeExpenseMember_2">General and Administrative Expense [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="GeneralAndAdministrativeExpenseMember" xlink:to="label_GeneralAndAdministrativeExpenseMember_2" xlink:title="label: GeneralAndAdministrativeExpenseMember to label_GeneralAndAdministrativeExpenseMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock" xlink:label="ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock" xlink:title="ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock" xml:lang="en-US" id="label_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock">Long-Lived Assets</link:label>
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    <link:label xlink:type="resource" xlink:label="label_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock" xml:lang="en-US" id="label_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock_2">Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]</link:label>
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    <link:label xlink:type="resource" xlink:label="label_IncomeStatementAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_IncomeStatementAbstract" xml:lang="en-US" id="label_IncomeStatementAbstract">CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="IncomeStatementLocationAxis" xlink:title="IncomeStatementLocationAxis" />
    <link:label xlink:type="resource" xlink:label="label_IncomeStatementLocationAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_IncomeStatementLocationAxis" xml:lang="en-US" id="label_IncomeStatementLocationAxis">Income Statement Location [Axis]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="IncomeStatementLocationAxis" xlink:to="label_IncomeStatementLocationAxis" xlink:title="label: IncomeStatementLocationAxis to label_IncomeStatementLocationAxis" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeTaxDisclosureAbstract" xlink:label="IncomeTaxDisclosureAbstract" xlink:title="IncomeTaxDisclosureAbstract" />
    <link:label xlink:type="resource" xlink:label="label_IncomeTaxDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_IncomeTaxDisclosureAbstract" xml:lang="en-US" id="label_IncomeTaxDisclosureAbstract">Income Taxes</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain" xlink:label="IncomeTaxAuthorityDomain" xlink:title="IncomeTaxAuthorityDomain" />
    <link:label xlink:type="resource" xlink:label="label_IncomeTaxAuthorityDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_IncomeTaxAuthorityDomain" xml:lang="en-US" id="label_IncomeTaxAuthorityDomain">Income Tax Authority [Domain]</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeTaxAuthorityAxis" xlink:label="IncomeTaxAuthorityAxis" xlink:title="IncomeTaxAuthorityAxis" />
    <link:label xlink:type="resource" xlink:label="label_IncomeTaxAuthorityAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_IncomeTaxAuthorityAxis" xml:lang="en-US" id="label_IncomeTaxAuthorityAxis">Income Tax Authority [Axis]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="IncomeTaxAuthorityAxis" xlink:to="label_IncomeTaxAuthorityAxis" xlink:title="label: IncomeTaxAuthorityAxis to label_IncomeTaxAuthorityAxis" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeTaxDisclosureTextBlock" xlink:label="IncomeTaxDisclosureTextBlock" xlink:title="IncomeTaxDisclosureTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_IncomeTaxDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_IncomeTaxDisclosureTextBlock" xml:lang="en-US" id="label_IncomeTaxDisclosureTextBlock">Income Taxes</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="IncomeTaxDisclosureTextBlock" xlink:to="label_IncomeTaxDisclosureTextBlock" xlink:title="label: IncomeTaxDisclosureTextBlock to label_IncomeTaxDisclosureTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_IncomeTaxDisclosureTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_IncomeTaxDisclosureTextBlock" xml:lang="en-US" id="label_IncomeTaxDisclosureTextBlock_2">Income Tax Disclosure [Text Block]</link:label>
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    <link:label xlink:type="resource" xlink:label="label_IncomeStatementLocationDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_IncomeStatementLocationDomain" xml:lang="en-US" id="label_IncomeStatementLocationDomain">Income Statement Location [Domain]</link:label>
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="IncreaseDecreaseInOtherNoncurrentAssets" xlink:to="label_IncreaseDecreaseInOtherNoncurrentAssets" xlink:title="label: IncreaseDecreaseInOtherNoncurrentAssets to label_IncreaseDecreaseInOtherNoncurrentAssets" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_IncreaseDecreaseInOtherNoncurrentAssets_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_IncreaseDecreaseInOtherNoncurrentAssets" xml:lang="en-US" id="label_IncreaseDecreaseInOtherNoncurrentAssets_2">Increase (Decrease) in Other Noncurrent Assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="IncreaseDecreaseInOtherNoncurrentAssets" xlink:to="label_IncreaseDecreaseInOtherNoncurrentAssets_2" xlink:title="label: IncreaseDecreaseInOtherNoncurrentAssets to label_IncreaseDecreaseInOtherNoncurrentAssets" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInDeferredRevenue" xlink:label="IncreaseDecreaseInDeferredRevenue" xlink:title="IncreaseDecreaseInDeferredRevenue" />
    <link:label xlink:type="resource" xlink:label="label_IncreaseDecreaseInDeferredRevenue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_IncreaseDecreaseInDeferredRevenue" xml:lang="en-US" id="label_IncreaseDecreaseInDeferredRevenue">Deferred revenue</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="IncreaseDecreaseInDeferredRevenue" xlink:to="label_IncreaseDecreaseInDeferredRevenue" xlink:title="label: IncreaseDecreaseInDeferredRevenue to label_IncreaseDecreaseInDeferredRevenue" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_IncreaseDecreaseInDeferredRevenue_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_IncreaseDecreaseInDeferredRevenue" xml:lang="en-US" id="label_IncreaseDecreaseInDeferredRevenue_2">Increase (Decrease) in Deferred Revenue</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="IncreaseDecreaseInDeferredRevenue" xlink:to="label_IncreaseDecreaseInDeferredRevenue_2" xlink:title="label: IncreaseDecreaseInDeferredRevenue to label_IncreaseDecreaseInDeferredRevenue" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:label="IncreaseDecreaseInOperatingCapitalAbstract" xlink:title="IncreaseDecreaseInOperatingCapitalAbstract" />
    <link:label xlink:type="resource" xlink:label="label_IncreaseDecreaseInOperatingCapitalAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_IncreaseDecreaseInOperatingCapitalAbstract" xml:lang="en-US" id="label_IncreaseDecreaseInOperatingCapitalAbstract">Changes in operating assets and liabilities:</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="label_IncreaseDecreaseInOperatingCapitalAbstract" xlink:title="label: IncreaseDecreaseInOperatingCapitalAbstract to label_IncreaseDecreaseInOperatingCapitalAbstract" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_IncreaseDecreaseInOperatingCapitalAbstract_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_IncreaseDecreaseInOperatingCapitalAbstract" xml:lang="en-US" id="label_IncreaseDecreaseInOperatingCapitalAbstract_2">Increase (Decrease) in Operating Capital [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="label_IncreaseDecreaseInOperatingCapitalAbstract_2" xlink:title="label: IncreaseDecreaseInOperatingCapitalAbstract to label_IncreaseDecreaseInOperatingCapitalAbstract" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:label="IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:title="IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" />
    <link:label xlink:type="resource" xlink:label="label_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:title="label_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xml:lang="en-US" id="label_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets">Prepaid expenses and other current assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:to="label_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:title="label: IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets to label_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xml:lang="en-US" id="label_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_2">Increase (Decrease) in Prepaid Expense and Other Assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:to="label_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_2" xlink:title="label: IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets to label_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:label="IncreaseDecreaseInStockholdersEquityRollForward" xlink:title="IncreaseDecreaseInStockholdersEquityRollForward" />
    <link:label xlink:type="resource" xlink:label="label_IncreaseDecreaseInStockholdersEquityRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_IncreaseDecreaseInStockholdersEquityRollForward" xml:lang="en-US" id="label_IncreaseDecreaseInStockholdersEquityRollForward">Increase (Decrease) in Stockholders' Equity [Roll Forward]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="label_IncreaseDecreaseInStockholdersEquityRollForward" xlink:title="label: IncreaseDecreaseInStockholdersEquityRollForward to label_IncreaseDecreaseInStockholdersEquityRollForward" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_IncreaseDecreaseInStockholdersEquityRollForward_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_IncreaseDecreaseInStockholdersEquityRollForward" xml:lang="en-US" id="label_IncreaseDecreaseInStockholdersEquityRollForward_2">Increase (Decrease) in Stockholders' Equity</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="label_IncreaseDecreaseInStockholdersEquityRollForward_2" xlink:title="label: IncreaseDecreaseInStockholdersEquityRollForward to label_IncreaseDecreaseInStockholdersEquityRollForward" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestExpense" xlink:label="InterestExpense" xlink:title="InterestExpense" />
    <link:label xlink:type="resource" xlink:label="label_InterestExpense" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:title="label_InterestExpense" xml:lang="en-US" id="label_InterestExpense">Interest expense</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="InterestExpense" xlink:to="label_InterestExpense" xlink:title="label: InterestExpense to label_InterestExpense" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_InterestExpense_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_InterestExpense" xml:lang="en-US" id="label_InterestExpense_2">Interest Expense</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="InterestExpense" xlink:to="label_InterestExpense_2" xlink:title="label: InterestExpense to label_InterestExpense" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InternalRevenueServiceIRSMember" xlink:label="InternalRevenueServiceIRSMember" xlink:title="InternalRevenueServiceIRSMember" />
    <link:label xlink:type="resource" xlink:label="label_InternalRevenueServiceIRSMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_InternalRevenueServiceIRSMember" xml:lang="en-US" id="label_InternalRevenueServiceIRSMember">U.S. federal</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="InternalRevenueServiceIRSMember" xlink:to="label_InternalRevenueServiceIRSMember" xlink:title="label: InternalRevenueServiceIRSMember to label_InternalRevenueServiceIRSMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_InternalRevenueServiceIRSMember_2" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_InternalRevenueServiceIRSMember" xml:lang="en-US" id="label_InternalRevenueServiceIRSMember_2">Federal</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="InternalRevenueServiceIRSMember" xlink:to="label_InternalRevenueServiceIRSMember_2" xlink:title="label: InternalRevenueServiceIRSMember to label_InternalRevenueServiceIRSMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_InternalRevenueServiceIRSMember_3" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_InternalRevenueServiceIRSMember" xml:lang="en-US" id="label_InternalRevenueServiceIRSMember_3">Internal Revenue Service (IRS) [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="InternalRevenueServiceIRSMember" xlink:to="label_InternalRevenueServiceIRSMember_3" xlink:title="label: InternalRevenueServiceIRSMember to label_InternalRevenueServiceIRSMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentIncomeInterest" xlink:label="InvestmentIncomeInterest" xlink:title="InvestmentIncomeInterest" />
    <link:label xlink:type="resource" xlink:label="label_InvestmentIncomeInterest" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_InvestmentIncomeInterest" xml:lang="en-US" id="label_InvestmentIncomeInterest">Interest income</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="InvestmentIncomeInterest" xlink:to="label_InvestmentIncomeInterest" xlink:title="label: InvestmentIncomeInterest to label_InvestmentIncomeInterest" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_InvestmentIncomeInterest_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_InvestmentIncomeInterest" xml:lang="en-US" id="label_InvestmentIncomeInterest_2">Investment Income, Interest</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="InvestmentIncomeInterest" xlink:to="label_InvestmentIncomeInterest_2" xlink:title="label: InvestmentIncomeInterest to label_InvestmentIncomeInterest" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LesseeLeasingArrangementsOperatingLeasesTermOfContract" xlink:label="LesseeLeasingArrangementsOperatingLeasesTermOfContract" xlink:title="LesseeLeasingArrangementsOperatingLeasesTermOfContract" />
    <link:label xlink:type="resource" xlink:label="label_LesseeLeasingArrangementsOperatingLeasesTermOfContract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_LesseeLeasingArrangementsOperatingLeasesTermOfContract" xml:lang="en-US" id="label_LesseeLeasingArrangementsOperatingLeasesTermOfContract">Term of lease</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="LesseeLeasingArrangementsOperatingLeasesTermOfContract" xlink:to="label_LesseeLeasingArrangementsOperatingLeasesTermOfContract" xlink:title="label: LesseeLeasingArrangementsOperatingLeasesTermOfContract to label_LesseeLeasingArrangementsOperatingLeasesTermOfContract" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_LesseeLeasingArrangementsOperatingLeasesTermOfContract_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_LesseeLeasingArrangementsOperatingLeasesTermOfContract" xml:lang="en-US" id="label_LesseeLeasingArrangementsOperatingLeasesTermOfContract_2">Lessee Leasing Arrangements, Operating Leases, Term of Contract</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="LesseeLeasingArrangementsOperatingLeasesTermOfContract" xlink:to="label_LesseeLeasingArrangementsOperatingLeasesTermOfContract_2" xlink:title="label: LesseeLeasingArrangementsOperatingLeasesTermOfContract to label_LesseeLeasingArrangementsOperatingLeasesTermOfContract" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LesseeLeasingArrangementsOperatingLeasesRenewalTerm" xlink:label="LesseeLeasingArrangementsOperatingLeasesRenewalTerm" xlink:title="LesseeLeasingArrangementsOperatingLeasesRenewalTerm" />
    <link:label xlink:type="resource" xlink:label="label_LesseeLeasingArrangementsOperatingLeasesRenewalTerm" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_LesseeLeasingArrangementsOperatingLeasesRenewalTerm" xml:lang="en-US" id="label_LesseeLeasingArrangementsOperatingLeasesRenewalTerm">Optional term to renew the lease</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="LesseeLeasingArrangementsOperatingLeasesRenewalTerm" xlink:to="label_LesseeLeasingArrangementsOperatingLeasesRenewalTerm" xlink:title="label: LesseeLeasingArrangementsOperatingLeasesRenewalTerm to label_LesseeLeasingArrangementsOperatingLeasesRenewalTerm" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_LesseeLeasingArrangementsOperatingLeasesRenewalTerm_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_LesseeLeasingArrangementsOperatingLeasesRenewalTerm" xml:lang="en-US" id="label_LesseeLeasingArrangementsOperatingLeasesRenewalTerm_2">Lessee Leasing Arrangements, Operating Leases, Renewal Term</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="LesseeLeasingArrangementsOperatingLeasesRenewalTerm" xlink:to="label_LesseeLeasingArrangementsOperatingLeasesRenewalTerm_2" xlink:title="label: LesseeLeasingArrangementsOperatingLeasesRenewalTerm to label_LesseeLeasingArrangementsOperatingLeasesRenewalTerm" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LeaseholdImprovementsMember" xlink:label="LeaseholdImprovementsMember" xlink:title="LeaseholdImprovementsMember" />
    <link:label xlink:type="resource" xlink:label="label_LeaseholdImprovementsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_LeaseholdImprovementsMember" xml:lang="en-US" id="label_LeaseholdImprovementsMember">Leasehold improvements</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="LeaseholdImprovementsMember" xlink:to="label_LeaseholdImprovementsMember" xlink:title="label: LeaseholdImprovementsMember to label_LeaseholdImprovementsMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_LeaseholdImprovementsMember_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_LeaseholdImprovementsMember" xml:lang="en-US" id="label_LeaseholdImprovementsMember_2">Leasehold Improvements [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="LeaseholdImprovementsMember" xlink:to="label_LeaseholdImprovementsMember_2" xlink:title="label: LeaseholdImprovementsMember to label_LeaseholdImprovementsMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="LiabilitiesCurrent" xlink:title="LiabilitiesCurrent" />
    <link:label xlink:type="resource" xlink:label="label_LiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:title="label_LiabilitiesCurrent" xml:lang="en-US" id="label_LiabilitiesCurrent">Total current liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="LiabilitiesCurrent" xlink:to="label_LiabilitiesCurrent" xlink:title="label: LiabilitiesCurrent to label_LiabilitiesCurrent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_LiabilitiesCurrent_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_LiabilitiesCurrent" xml:lang="en-US" id="label_LiabilitiesCurrent_2">Liabilities, Current</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="LiabilitiesCurrent" xlink:to="label_LiabilitiesCurrent_2" xlink:title="label: LiabilitiesCurrent to label_LiabilitiesCurrent" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="LiabilitiesAndStockholdersEquity" xlink:title="LiabilitiesAndStockholdersEquity" />
    <link:label xlink:type="resource" xlink:label="label_LiabilitiesAndStockholdersEquity" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:title="label_LiabilitiesAndStockholdersEquity" xml:lang="en-US" id="label_LiabilitiesAndStockholdersEquity">Total liabilities and stockholders' equity</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="LiabilitiesAndStockholdersEquity" xlink:to="label_LiabilitiesAndStockholdersEquity" xlink:title="label: LiabilitiesAndStockholdersEquity to label_LiabilitiesAndStockholdersEquity" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_LiabilitiesAndStockholdersEquity_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_LiabilitiesAndStockholdersEquity" xml:lang="en-US" id="label_LiabilitiesAndStockholdersEquity_2">Liabilities and Equity</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="LiabilitiesAndStockholdersEquity" xlink:to="label_LiabilitiesAndStockholdersEquity_2" xlink:title="label: LiabilitiesAndStockholdersEquity to label_LiabilitiesAndStockholdersEquity" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:label="LiabilitiesCurrentAbstract" xlink:title="LiabilitiesCurrentAbstract" />
    <link:label xlink:type="resource" xlink:label="label_LiabilitiesCurrentAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_LiabilitiesCurrentAbstract" xml:lang="en-US" id="label_LiabilitiesCurrentAbstract">Current liabilities:</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="LiabilitiesCurrentAbstract" xlink:to="label_LiabilitiesCurrentAbstract" xlink:title="label: LiabilitiesCurrentAbstract to label_LiabilitiesCurrentAbstract" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_LiabilitiesCurrentAbstract_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_LiabilitiesCurrentAbstract" xml:lang="en-US" id="label_LiabilitiesCurrentAbstract_2">Liabilities, Current [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="LiabilitiesCurrentAbstract" xlink:to="label_LiabilitiesCurrentAbstract_2" xlink:title="label: LiabilitiesCurrentAbstract to label_LiabilitiesCurrentAbstract" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_LiabilitiesCurrentAbstract_3" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_LiabilitiesCurrentAbstract" xml:lang="en-US" id="label_LiabilitiesCurrentAbstract_3">Liabilities:</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="LiabilitiesCurrentAbstract" xlink:to="label_LiabilitiesCurrentAbstract_3" xlink:title="label: LiabilitiesCurrentAbstract to label_LiabilitiesCurrentAbstract" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_Liabilities" xlink:label="Liabilities" xlink:title="Liabilities" />
    <link:label xlink:type="resource" xlink:label="label_Liabilities" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:title="label_Liabilities" xml:lang="en-US" id="label_Liabilities">Total Liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="Liabilities" xlink:to="label_Liabilities" xlink:title="label: Liabilities to label_Liabilities" use="optional" />
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    <link:label xlink:type="resource" xlink:label="label_NonoperatingIncomeExpense_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_NonoperatingIncomeExpense" xml:lang="en-US" id="label_NonoperatingIncomeExpense_2">Nonoperating Income (Expense)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="NonoperatingIncomeExpense" xlink:to="label_NonoperatingIncomeExpense_2" xlink:title="label: NonoperatingIncomeExpense to label_NonoperatingIncomeExpense" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NonoperatingIncomeExpenseAbstract" xlink:label="NonoperatingIncomeExpenseAbstract" xlink:title="NonoperatingIncomeExpenseAbstract" />
    <link:label xlink:type="resource" xlink:label="label_NonoperatingIncomeExpenseAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_NonoperatingIncomeExpenseAbstract" xml:lang="en-US" id="label_NonoperatingIncomeExpenseAbstract">Other income (expense):</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="NonoperatingIncomeExpenseAbstract" xlink:to="label_NonoperatingIncomeExpenseAbstract" xlink:title="label: NonoperatingIncomeExpenseAbstract to label_NonoperatingIncomeExpenseAbstract" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_NonoperatingIncomeExpenseAbstract_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_NonoperatingIncomeExpenseAbstract" xml:lang="en-US" id="label_NonoperatingIncomeExpenseAbstract_2">Nonoperating Income (Expense) [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="NonoperatingIncomeExpenseAbstract" xlink:to="label_NonoperatingIncomeExpenseAbstract_2" xlink:title="label: NonoperatingIncomeExpenseAbstract to label_NonoperatingIncomeExpenseAbstract" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NotesIssued1" xlink:label="NotesIssued1" xlink:title="NotesIssued1" />
    <link:label xlink:type="resource" xlink:label="label_NotesIssued1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_NotesIssued1" xml:lang="en-US" id="label_NotesIssued1">Issuance of convertible notes in satisfaction of accrued expenses</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="NotesIssued1" xlink:to="label_NotesIssued1" xlink:title="label: NotesIssued1 to label_NotesIssued1" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_NotesIssued1_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_NotesIssued1" xml:lang="en-US" id="label_NotesIssued1_2">Notes Issued</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="NotesIssued1" xlink:to="label_NotesIssued1_2" xlink:title="label: NotesIssued1 to label_NotesIssued1" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NumberOfOperatingSegments" xlink:label="NumberOfOperatingSegments" xlink:title="NumberOfOperatingSegments" />
    <link:label xlink:type="resource" xlink:label="label_NumberOfOperatingSegments" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_NumberOfOperatingSegments" xml:lang="en-US" id="label_NumberOfOperatingSegments">Number of operating segments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="NumberOfOperatingSegments" xlink:to="label_NumberOfOperatingSegments" xlink:title="label: NumberOfOperatingSegments to label_NumberOfOperatingSegments" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_NumberOfOperatingSegments_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_NumberOfOperatingSegments" xml:lang="en-US" id="label_NumberOfOperatingSegments_2">Number of Operating Segments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="NumberOfOperatingSegments" xlink:to="label_NumberOfOperatingSegments_2" xlink:title="label: NumberOfOperatingSegments to label_NumberOfOperatingSegments" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OfficeEquipmentMember" xlink:label="OfficeEquipmentMember" xlink:title="OfficeEquipmentMember" />
    <link:label xlink:type="resource" xlink:label="label_OfficeEquipmentMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_OfficeEquipmentMember" xml:lang="en-US" id="label_OfficeEquipmentMember">Office and computer equipment</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OfficeEquipmentMember" xlink:to="label_OfficeEquipmentMember" xlink:title="label: OfficeEquipmentMember to label_OfficeEquipmentMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OfficeEquipmentMember_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_OfficeEquipmentMember" xml:lang="en-US" id="label_OfficeEquipmentMember_2">Office Equipment [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OfficeEquipmentMember" xlink:to="label_OfficeEquipmentMember_2" xlink:title="label: OfficeEquipmentMember to label_OfficeEquipmentMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueAbstract" xlink:label="OperatingLeasesFutureMinimumPaymentsDueAbstract" xlink:title="OperatingLeasesFutureMinimumPaymentsDueAbstract" />
    <link:label xlink:type="resource" xlink:label="label_OperatingLeasesFutureMinimumPaymentsDueAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_OperatingLeasesFutureMinimumPaymentsDueAbstract" xml:lang="en-US" id="label_OperatingLeasesFutureMinimumPaymentsDueAbstract">Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingLeasesFutureMinimumPaymentsDueAbstract" xlink:to="label_OperatingLeasesFutureMinimumPaymentsDueAbstract" xlink:title="label: OperatingLeasesFutureMinimumPaymentsDueAbstract to label_OperatingLeasesFutureMinimumPaymentsDueAbstract" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OperatingLeasesFutureMinimumPaymentsDueAbstract_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_OperatingLeasesFutureMinimumPaymentsDueAbstract" xml:lang="en-US" id="label_OperatingLeasesFutureMinimumPaymentsDueAbstract_2">Minimum future rent payments under the lease agreement</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingLeasesFutureMinimumPaymentsDueAbstract" xlink:to="label_OperatingLeasesFutureMinimumPaymentsDueAbstract_2" xlink:title="label: OperatingLeasesFutureMinimumPaymentsDueAbstract to label_OperatingLeasesFutureMinimumPaymentsDueAbstract" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingExpensesAbstract" xlink:label="OperatingExpensesAbstract" xlink:title="OperatingExpensesAbstract" />
    <link:label xlink:type="resource" xlink:label="label_OperatingExpensesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_OperatingExpensesAbstract" xml:lang="en-US" id="label_OperatingExpensesAbstract">Operating expenses:</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingExpensesAbstract" xlink:to="label_OperatingExpensesAbstract" xlink:title="label: OperatingExpensesAbstract to label_OperatingExpensesAbstract" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OperatingExpensesAbstract_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_OperatingExpensesAbstract" xml:lang="en-US" id="label_OperatingExpensesAbstract_2">Operating Expenses [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingExpensesAbstract" xlink:to="label_OperatingExpensesAbstract_2" xlink:title="label: OperatingExpensesAbstract to label_OperatingExpensesAbstract" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingExpenses" xlink:label="OperatingExpenses" xlink:title="OperatingExpenses" />
    <link:label xlink:type="resource" xlink:label="label_OperatingExpenses" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:title="label_OperatingExpenses" xml:lang="en-US" id="label_OperatingExpenses">Total operating expenses</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingExpenses" xlink:to="label_OperatingExpenses" xlink:title="label: OperatingExpenses to label_OperatingExpenses" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OperatingExpenses_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_OperatingExpenses" xml:lang="en-US" id="label_OperatingExpenses_2">Operating Expenses</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingExpenses" xlink:to="label_OperatingExpenses_2" xlink:title="label: OperatingExpenses to label_OperatingExpenses" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OperatingExpenses_3" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_OperatingExpenses" xml:lang="en-US" id="label_OperatingExpenses_3">Total operating expenses</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingExpenses" xlink:to="label_OperatingExpenses_3" xlink:title="label: OperatingExpenses to label_OperatingExpenses" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLeasesRentExpenseNet" xlink:label="OperatingLeasesRentExpenseNet" xlink:title="OperatingLeasesRentExpenseNet" />
    <link:label xlink:type="resource" xlink:label="label_OperatingLeasesRentExpenseNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_OperatingLeasesRentExpenseNet" xml:lang="en-US" id="label_OperatingLeasesRentExpenseNet">Total rent expense</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingLeasesRentExpenseNet" xlink:to="label_OperatingLeasesRentExpenseNet" xlink:title="label: OperatingLeasesRentExpenseNet to label_OperatingLeasesRentExpenseNet" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OperatingLeasesRentExpenseNet_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_OperatingLeasesRentExpenseNet" xml:lang="en-US" id="label_OperatingLeasesRentExpenseNet_2">Operating Leases, Rent Expense, Net</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingLeasesRentExpenseNet" xlink:to="label_OperatingLeasesRentExpenseNet_2" xlink:title="label: OperatingLeasesRentExpenseNet to label_OperatingLeasesRentExpenseNet" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent" xlink:label="OperatingLeasesFutureMinimumPaymentsDueCurrent" xlink:title="OperatingLeasesFutureMinimumPaymentsDueCurrent" />
    <link:label xlink:type="resource" xlink:label="label_OperatingLeasesFutureMinimumPaymentsDueCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_OperatingLeasesFutureMinimumPaymentsDueCurrent" xml:lang="en-US" id="label_OperatingLeasesFutureMinimumPaymentsDueCurrent">Operating Leases, Future Minimum Payments Due, Next Twelve Months</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingLeasesFutureMinimumPaymentsDueCurrent" xlink:to="label_OperatingLeasesFutureMinimumPaymentsDueCurrent" xlink:title="label: OperatingLeasesFutureMinimumPaymentsDueCurrent to label_OperatingLeasesFutureMinimumPaymentsDueCurrent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OperatingLeasesFutureMinimumPaymentsDueCurrent_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_OperatingLeasesFutureMinimumPaymentsDueCurrent" xml:lang="en-US" id="label_OperatingLeasesFutureMinimumPaymentsDueCurrent_2">2014</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingLeasesFutureMinimumPaymentsDueCurrent" xlink:to="label_OperatingLeasesFutureMinimumPaymentsDueCurrent_2" xlink:title="label: OperatingLeasesFutureMinimumPaymentsDueCurrent to label_OperatingLeasesFutureMinimumPaymentsDueCurrent" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="OperatingIncomeLoss" xlink:title="OperatingIncomeLoss" />
    <link:label xlink:type="resource" xlink:label="label_OperatingIncomeLoss" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:title="label_OperatingIncomeLoss" xml:lang="en-US" id="label_OperatingIncomeLoss">Loss from operations</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingIncomeLoss" xlink:to="label_OperatingIncomeLoss" xlink:title="label: OperatingIncomeLoss to label_OperatingIncomeLoss" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OperatingIncomeLoss_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_OperatingIncomeLoss" xml:lang="en-US" id="label_OperatingIncomeLoss_2">Operating Income (Loss)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingIncomeLoss" xlink:to="label_OperatingIncomeLoss_2" xlink:title="label: OperatingIncomeLoss to label_OperatingIncomeLoss" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLeasesRentExpenseContingentRentals" xlink:label="OperatingLeasesRentExpenseContingentRentals" xlink:title="OperatingLeasesRentExpenseContingentRentals" />
    <link:label xlink:type="resource" xlink:label="label_OperatingLeasesRentExpenseContingentRentals" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_OperatingLeasesRentExpenseContingentRentals" xml:lang="en-US" id="label_OperatingLeasesRentExpenseContingentRentals">Maximum rent until which base rent rises periodically</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingLeasesRentExpenseContingentRentals" xlink:to="label_OperatingLeasesRentExpenseContingentRentals" xlink:title="label: OperatingLeasesRentExpenseContingentRentals to label_OperatingLeasesRentExpenseContingentRentals" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OperatingLeasesRentExpenseContingentRentals_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_OperatingLeasesRentExpenseContingentRentals" xml:lang="en-US" id="label_OperatingLeasesRentExpenseContingentRentals_2">Operating Leases, Rent Expense, Contingent Rentals</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingLeasesRentExpenseContingentRentals" xlink:to="label_OperatingLeasesRentExpenseContingentRentals_2" xlink:title="label: OperatingLeasesRentExpenseContingentRentals to label_OperatingLeasesRentExpenseContingentRentals" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLossCarryforwardsTable" xlink:label="OperatingLossCarryforwardsTable" xlink:title="OperatingLossCarryforwardsTable" />
    <link:label xlink:type="resource" xlink:label="label_OperatingLossCarryforwardsTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_OperatingLossCarryforwardsTable" xml:lang="en-US" id="label_OperatingLossCarryforwardsTable">Operating Loss Carryforwards [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingLossCarryforwardsTable" xlink:to="label_OperatingLossCarryforwardsTable" xlink:title="label: OperatingLossCarryforwardsTable to label_OperatingLossCarryforwardsTable" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLossCarryforwardsLineItems" xlink:label="OperatingLossCarryforwardsLineItems" xlink:title="OperatingLossCarryforwardsLineItems" />
    <link:label xlink:type="resource" xlink:label="label_OperatingLossCarryforwardsLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_OperatingLossCarryforwardsLineItems" xml:lang="en-US" id="label_OperatingLossCarryforwardsLineItems">Income Taxes</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingLossCarryforwardsLineItems" xlink:to="label_OperatingLossCarryforwardsLineItems" xlink:title="label: OperatingLossCarryforwardsLineItems to label_OperatingLossCarryforwardsLineItems" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OperatingLossCarryforwardsLineItems_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_OperatingLossCarryforwardsLineItems" xml:lang="en-US" id="label_OperatingLossCarryforwardsLineItems_2">Operating Loss Carryforwards [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingLossCarryforwardsLineItems" xlink:to="label_OperatingLossCarryforwardsLineItems_2" xlink:title="label: OperatingLossCarryforwardsLineItems to label_OperatingLossCarryforwardsLineItems" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:label="OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:title="OperatingLeasesFutureMinimumPaymentsDueInTwoYears" />
    <link:label xlink:type="resource" xlink:label="label_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xml:lang="en-US" id="label_OperatingLeasesFutureMinimumPaymentsDueInTwoYears">Operating Leases, Future Minimum Payments, Due in Two Years</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:to="label_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:title="label: OperatingLeasesFutureMinimumPaymentsDueInTwoYears to label_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OperatingLeasesFutureMinimumPaymentsDueInTwoYears_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xml:lang="en-US" id="label_OperatingLeasesFutureMinimumPaymentsDueInTwoYears_2">2015</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:to="label_OperatingLeasesFutureMinimumPaymentsDueInTwoYears_2" xlink:title="label: OperatingLeasesFutureMinimumPaymentsDueInTwoYears to label_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLeasesRentExpenseMinimumRentals" xlink:label="OperatingLeasesRentExpenseMinimumRentals" xlink:title="OperatingLeasesRentExpenseMinimumRentals" />
    <link:label xlink:type="resource" xlink:label="label_OperatingLeasesRentExpenseMinimumRentals" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_OperatingLeasesRentExpenseMinimumRentals" xml:lang="en-US" id="label_OperatingLeasesRentExpenseMinimumRentals">Initial annual base rent</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingLeasesRentExpenseMinimumRentals" xlink:to="label_OperatingLeasesRentExpenseMinimumRentals" xlink:title="label: OperatingLeasesRentExpenseMinimumRentals to label_OperatingLeasesRentExpenseMinimumRentals" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OperatingLeasesRentExpenseMinimumRentals_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_OperatingLeasesRentExpenseMinimumRentals" xml:lang="en-US" id="label_OperatingLeasesRentExpenseMinimumRentals_2">Operating Leases, Rent Expense, Minimum Rentals</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingLeasesRentExpenseMinimumRentals" xlink:to="label_OperatingLeasesRentExpenseMinimumRentals_2" xlink:title="label: OperatingLeasesRentExpenseMinimumRentals to label_OperatingLeasesRentExpenseMinimumRentals" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDue" xlink:label="OperatingLeasesFutureMinimumPaymentsDue" xlink:title="OperatingLeasesFutureMinimumPaymentsDue" />
    <link:label xlink:type="resource" xlink:label="label_OperatingLeasesFutureMinimumPaymentsDue" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:title="label_OperatingLeasesFutureMinimumPaymentsDue" xml:lang="en-US" id="label_OperatingLeasesFutureMinimumPaymentsDue">Total future minimum lease payments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingLeasesFutureMinimumPaymentsDue" xlink:to="label_OperatingLeasesFutureMinimumPaymentsDue" xlink:title="label: OperatingLeasesFutureMinimumPaymentsDue to label_OperatingLeasesFutureMinimumPaymentsDue" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OperatingLeasesFutureMinimumPaymentsDue_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_OperatingLeasesFutureMinimumPaymentsDue" xml:lang="en-US" id="label_OperatingLeasesFutureMinimumPaymentsDue_2">Operating Leases, Future Minimum Payments Due</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingLeasesFutureMinimumPaymentsDue" xlink:to="label_OperatingLeasesFutureMinimumPaymentsDue_2" xlink:title="label: OperatingLeasesFutureMinimumPaymentsDue to label_OperatingLeasesFutureMinimumPaymentsDue" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLossCarryforwards" xlink:label="OperatingLossCarryforwards" xlink:title="OperatingLossCarryforwards" />
    <link:label xlink:type="resource" xlink:label="label_OperatingLossCarryforwards" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_OperatingLossCarryforwards" xml:lang="en-US" id="label_OperatingLossCarryforwards">Net operating loss carryforwards</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingLossCarryforwards" xlink:to="label_OperatingLossCarryforwards" xlink:title="label: OperatingLossCarryforwards to label_OperatingLossCarryforwards" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OperatingLossCarryforwards_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_OperatingLossCarryforwards" xml:lang="en-US" id="label_OperatingLossCarryforwards_2">Operating Loss Carryforwards</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OperatingLossCarryforwards" xlink:to="label_OperatingLossCarryforwards_2" xlink:title="label: OperatingLossCarryforwards to label_OperatingLossCarryforwards" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:label="OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:title="OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" />
    <link:label xlink:type="resource" xlink:label="label_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xml:lang="en-US" id="label_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract">Organization and Operations</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:to="label_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:title="label: OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract to label_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" xlink:label="OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" xlink:title="OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" xml:lang="en-US" id="label_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock">Organization and Operations</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" xlink:to="label_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" xlink:title="label: OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock to label_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" xml:lang="en-US" id="label_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock_2">Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" xlink:to="label_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock_2" xlink:title="label: OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock to label_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="OtherAssetsNoncurrent" xlink:title="OtherAssetsNoncurrent" />
    <link:label xlink:type="resource" xlink:label="label_OtherAssetsNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_OtherAssetsNoncurrent" xml:lang="en-US" id="label_OtherAssetsNoncurrent">Other assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OtherAssetsNoncurrent" xlink:to="label_OtherAssetsNoncurrent" xlink:title="label: OtherAssetsNoncurrent to label_OtherAssetsNoncurrent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OtherAssetsNoncurrent_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_OtherAssetsNoncurrent" xml:lang="en-US" id="label_OtherAssetsNoncurrent_2">Other Assets, Noncurrent</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OtherAssetsNoncurrent" xlink:to="label_OtherAssetsNoncurrent_2" xlink:title="label: OtherAssetsNoncurrent to label_OtherAssetsNoncurrent" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="OtherNonoperatingIncomeExpense" xlink:title="OtherNonoperatingIncomeExpense" />
    <link:label xlink:type="resource" xlink:label="label_OtherNonoperatingIncomeExpense" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:title="label_OtherNonoperatingIncomeExpense" xml:lang="en-US" id="label_OtherNonoperatingIncomeExpense">Total other income (expense)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OtherNonoperatingIncomeExpense" xlink:to="label_OtherNonoperatingIncomeExpense" xlink:title="label: OtherNonoperatingIncomeExpense to label_OtherNonoperatingIncomeExpense" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OtherNonoperatingIncomeExpense_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_OtherNonoperatingIncomeExpense" xml:lang="en-US" id="label_OtherNonoperatingIncomeExpense_2">Other Nonoperating Income (Expense)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OtherNonoperatingIncomeExpense" xlink:to="label_OtherNonoperatingIncomeExpense_2" xlink:title="label: OtherNonoperatingIncomeExpense to label_OtherNonoperatingIncomeExpense" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OtherNonoperatingIncomeExpense_3" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_OtherNonoperatingIncomeExpense" xml:lang="en-US" id="label_OtherNonoperatingIncomeExpense_3">Total other income (expense)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OtherNonoperatingIncomeExpense" xlink:to="label_OtherNonoperatingIncomeExpense_3" xlink:title="label: OtherNonoperatingIncomeExpense to label_OtherNonoperatingIncomeExpense" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="OtherLiabilitiesNoncurrent" xlink:title="OtherLiabilitiesNoncurrent" />
    <link:label xlink:type="resource" xlink:label="label_OtherLiabilitiesNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_OtherLiabilitiesNoncurrent" xml:lang="en-US" id="label_OtherLiabilitiesNoncurrent">Other long-term liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OtherLiabilitiesNoncurrent" xlink:to="label_OtherLiabilitiesNoncurrent" xlink:title="label: OtherLiabilitiesNoncurrent to label_OtherLiabilitiesNoncurrent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OtherLiabilitiesNoncurrent_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_OtherLiabilitiesNoncurrent" xml:lang="en-US" id="label_OtherLiabilitiesNoncurrent_2">Other Liabilities, Noncurrent</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OtherLiabilitiesNoncurrent" xlink:to="label_OtherLiabilitiesNoncurrent_2" xlink:title="label: OtherLiabilitiesNoncurrent to label_OtherLiabilitiesNoncurrent" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherLiabilitiesCurrent" xlink:label="OtherLiabilitiesCurrent" xlink:title="OtherLiabilitiesCurrent" />
    <link:label xlink:type="resource" xlink:label="label_OtherLiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_OtherLiabilitiesCurrent" xml:lang="en-US" id="label_OtherLiabilitiesCurrent">Other current liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OtherLiabilitiesCurrent" xlink:to="label_OtherLiabilitiesCurrent" xlink:title="label: OtherLiabilitiesCurrent to label_OtherLiabilitiesCurrent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OtherLiabilitiesCurrent_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_OtherLiabilitiesCurrent" xml:lang="en-US" id="label_OtherLiabilitiesCurrent_2">Other Liabilities, Current</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OtherLiabilitiesCurrent" xlink:to="label_OtherLiabilitiesCurrent_2" xlink:title="label: OtherLiabilitiesCurrent to label_OtherLiabilitiesCurrent" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherAccruedLiabilitiesCurrent" xlink:label="OtherAccruedLiabilitiesCurrent" xlink:title="OtherAccruedLiabilitiesCurrent" />
    <link:label xlink:type="resource" xlink:label="label_OtherAccruedLiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_OtherAccruedLiabilitiesCurrent" xml:lang="en-US" id="label_OtherAccruedLiabilitiesCurrent">Other</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OtherAccruedLiabilitiesCurrent" xlink:to="label_OtherAccruedLiabilitiesCurrent" xlink:title="label: OtherAccruedLiabilitiesCurrent to label_OtherAccruedLiabilitiesCurrent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_OtherAccruedLiabilitiesCurrent_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_OtherAccruedLiabilitiesCurrent" xml:lang="en-US" id="label_OtherAccruedLiabilitiesCurrent_2">Other Accrued Liabilities, Current</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="OtherAccruedLiabilitiesCurrent" xlink:to="label_OtherAccruedLiabilitiesCurrent_2" xlink:title="label: OtherAccruedLiabilitiesCurrent to label_OtherAccruedLiabilitiesCurrent" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaidInKindInterest" xlink:label="PaidInKindInterest" xlink:title="PaidInKindInterest" />
    <link:label xlink:type="resource" xlink:label="label_PaidInKindInterest" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_PaidInKindInterest" xml:lang="en-US" id="label_PaidInKindInterest">Noncash interest expense</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PaidInKindInterest" xlink:to="label_PaidInKindInterest" xlink:title="label: PaidInKindInterest to label_PaidInKindInterest" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_PaidInKindInterest_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_PaidInKindInterest" xml:lang="en-US" id="label_PaidInKindInterest_2">Paid-in-Kind Interest</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PaidInKindInterest" xlink:to="label_PaidInKindInterest_2" xlink:title="label: PaidInKindInterest to label_PaidInKindInterest" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="PaymentsToAcquirePropertyPlantAndEquipment" xlink:title="PaymentsToAcquirePropertyPlantAndEquipment" />
    <link:label xlink:type="resource" xlink:label="label_PaymentsToAcquirePropertyPlantAndEquipment" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:title="label_PaymentsToAcquirePropertyPlantAndEquipment" xml:lang="en-US" id="label_PaymentsToAcquirePropertyPlantAndEquipment">Purchases of property and equipment</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PaymentsToAcquirePropertyPlantAndEquipment" xlink:to="label_PaymentsToAcquirePropertyPlantAndEquipment" xlink:title="label: PaymentsToAcquirePropertyPlantAndEquipment to label_PaymentsToAcquirePropertyPlantAndEquipment" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_PaymentsToAcquirePropertyPlantAndEquipment_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_PaymentsToAcquirePropertyPlantAndEquipment" xml:lang="en-US" id="label_PaymentsToAcquirePropertyPlantAndEquipment_2">Payments to Acquire Property, Plant, and Equipment</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PaymentsToAcquirePropertyPlantAndEquipment" xlink:to="label_PaymentsToAcquirePropertyPlantAndEquipment_2" xlink:title="label: PaymentsToAcquirePropertyPlantAndEquipment to label_PaymentsToAcquirePropertyPlantAndEquipment" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaymentsOfStockIssuanceCosts" xlink:label="PaymentsOfStockIssuanceCosts" xlink:title="PaymentsOfStockIssuanceCosts" />
    <link:label xlink:type="resource" xlink:label="label_PaymentsOfStockIssuanceCosts" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:title="label_PaymentsOfStockIssuanceCosts" xml:lang="en-US" id="label_PaymentsOfStockIssuanceCosts">Issuance costs from the sale of common stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PaymentsOfStockIssuanceCosts" xlink:to="label_PaymentsOfStockIssuanceCosts" xlink:title="label: PaymentsOfStockIssuanceCosts to label_PaymentsOfStockIssuanceCosts" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_PaymentsOfStockIssuanceCosts_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_PaymentsOfStockIssuanceCosts" xml:lang="en-US" id="label_PaymentsOfStockIssuanceCosts_2">Payments of Stock Issuance Costs</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PaymentsOfStockIssuanceCosts" xlink:to="label_PaymentsOfStockIssuanceCosts_2" xlink:title="label: PaymentsOfStockIssuanceCosts to label_PaymentsOfStockIssuanceCosts" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="PlanNameDomain" xlink:title="PlanNameDomain" />
    <link:label xlink:type="resource" xlink:label="label_PlanNameDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_PlanNameDomain" xml:lang="en-US" id="label_PlanNameDomain">Plan Name [Domain]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PlanNameDomain" xlink:to="label_PlanNameDomain" xlink:title="label: PlanNameDomain to label_PlanNameDomain" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="PlanNameAxis" xlink:title="PlanNameAxis" />
    <link:label xlink:type="resource" xlink:label="label_PlanNameAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_PlanNameAxis" xml:lang="en-US" id="label_PlanNameAxis">Plan Name [Axis]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PlanNameAxis" xlink:to="label_PlanNameAxis" xlink:title="label: PlanNameAxis to label_PlanNameAxis" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockParOrStatedValuePerShare" xlink:label="PreferredStockParOrStatedValuePerShare" xlink:title="PreferredStockParOrStatedValuePerShare" />
    <link:label xlink:type="resource" xlink:label="label_PreferredStockParOrStatedValuePerShare" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_PreferredStockParOrStatedValuePerShare" xml:lang="en-US" id="label_PreferredStockParOrStatedValuePerShare">Convertible preferred stock, par value (in dollars per share)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PreferredStockParOrStatedValuePerShare" xlink:to="label_PreferredStockParOrStatedValuePerShare" xlink:title="label: PreferredStockParOrStatedValuePerShare to label_PreferredStockParOrStatedValuePerShare" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_PreferredStockParOrStatedValuePerShare_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_PreferredStockParOrStatedValuePerShare" xml:lang="en-US" id="label_PreferredStockParOrStatedValuePerShare_2">Preferred Stock, Par or Stated Value Per Share</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PreferredStockParOrStatedValuePerShare" xlink:to="label_PreferredStockParOrStatedValuePerShare_2" xlink:title="label: PreferredStockParOrStatedValuePerShare to label_PreferredStockParOrStatedValuePerShare" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockValue" xlink:label="PreferredStockValue" xlink:title="PreferredStockValue" />
    <link:label xlink:type="resource" xlink:label="label_PreferredStockValue" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_PreferredStockValue" xml:lang="en-US" id="label_PreferredStockValue">Convertible preferred stock, $0.0001 par value; 5,000,000 shares authorized; none issued and outstanding</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PreferredStockValue" xlink:to="label_PreferredStockValue" xlink:title="label: PreferredStockValue to label_PreferredStockValue" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_PreferredStockValue_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_PreferredStockValue" xml:lang="en-US" id="label_PreferredStockValue_2">Preferred Stock, Value, Issued</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PreferredStockValue" xlink:to="label_PreferredStockValue_2" xlink:title="label: PreferredStockValue to label_PreferredStockValue" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockSharesIssued" xlink:label="PreferredStockSharesIssued" xlink:title="PreferredStockSharesIssued" />
    <link:label xlink:type="resource" xlink:label="label_PreferredStockSharesIssued" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_PreferredStockSharesIssued" xml:lang="en-US" id="label_PreferredStockSharesIssued">Convertible preferred stock, shares issued</link:label>
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    <link:label xlink:type="resource" xlink:label="label_PreferredStockSharesIssued_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_PreferredStockSharesIssued" xml:lang="en-US" id="label_PreferredStockSharesIssued_2">Preferred Stock, Shares Issued</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PreferredStockSharesIssued" xlink:to="label_PreferredStockSharesIssued_2" xlink:title="label: PreferredStockSharesIssued to label_PreferredStockSharesIssued" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:label="PreferredStockSharesAuthorized" xlink:title="PreferredStockSharesAuthorized" />
    <link:label xlink:type="resource" xlink:label="label_PreferredStockSharesAuthorized" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_PreferredStockSharesAuthorized" xml:lang="en-US" id="label_PreferredStockSharesAuthorized">Convertible preferred stock, shares authorized</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PreferredStockSharesAuthorized" xlink:to="label_PreferredStockSharesAuthorized" xlink:title="label: PreferredStockSharesAuthorized to label_PreferredStockSharesAuthorized" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_PreferredStockSharesAuthorized_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_PreferredStockSharesAuthorized" xml:lang="en-US" id="label_PreferredStockSharesAuthorized_2">Preferred Stock, Shares Authorized</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PreferredStockSharesAuthorized" xlink:to="label_PreferredStockSharesAuthorized_2" xlink:title="label: PreferredStockSharesAuthorized to label_PreferredStockSharesAuthorized" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockSharesOutstanding" xlink:label="PreferredStockSharesOutstanding" xlink:title="PreferredStockSharesOutstanding" />
    <link:label xlink:type="resource" xlink:label="label_PreferredStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_PreferredStockSharesOutstanding" xml:lang="en-US" id="label_PreferredStockSharesOutstanding">Convertible preferred stock, shares outstanding</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PreferredStockSharesOutstanding" xlink:to="label_PreferredStockSharesOutstanding" xlink:title="label: PreferredStockSharesOutstanding to label_PreferredStockSharesOutstanding" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_PreferredStockSharesOutstanding_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_PreferredStockSharesOutstanding" xml:lang="en-US" id="label_PreferredStockSharesOutstanding_2">Preferred Stock, Shares Outstanding</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PreferredStockSharesOutstanding" xlink:to="label_PreferredStockSharesOutstanding_2" xlink:title="label: PreferredStockSharesOutstanding to label_PreferredStockSharesOutstanding" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockMember" xlink:label="PreferredStockMember" xlink:title="PreferredStockMember" />
    <link:label xlink:type="resource" xlink:label="label_PreferredStockMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_PreferredStockMember" xml:lang="en-US" id="label_PreferredStockMember">Preferred stock financings</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PreferredStockMember" xlink:to="label_PreferredStockMember" xlink:title="label: PreferredStockMember to label_PreferredStockMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_PreferredStockMember_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_PreferredStockMember" xml:lang="en-US" id="label_PreferredStockMember_2">Preferred Stock [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PreferredStockMember" xlink:to="label_PreferredStockMember_2" xlink:title="label: PreferredStockMember to label_PreferredStockMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:label="PrepaidExpenseAndOtherAssetsCurrent" xlink:title="PrepaidExpenseAndOtherAssetsCurrent" />
    <link:label xlink:type="resource" xlink:label="label_PrepaidExpenseAndOtherAssetsCurrent" xlink:role="http://www.xbrl.org/2003/role/positiveLabel" xlink:title="label_PrepaidExpenseAndOtherAssetsCurrent" xml:lang="en-US" id="label_PrepaidExpenseAndOtherAssetsCurrent">Prepaid Expenses and other current assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PrepaidExpenseAndOtherAssetsCurrent" xlink:to="label_PrepaidExpenseAndOtherAssetsCurrent" xlink:title="label: PrepaidExpenseAndOtherAssetsCurrent to label_PrepaidExpenseAndOtherAssetsCurrent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_PrepaidExpenseAndOtherAssetsCurrent_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_PrepaidExpenseAndOtherAssetsCurrent" xml:lang="en-US" id="label_PrepaidExpenseAndOtherAssetsCurrent_2">Prepaid Expense and Other Assets, Current</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PrepaidExpenseAndOtherAssetsCurrent" xlink:to="label_PrepaidExpenseAndOtherAssetsCurrent_2" xlink:title="label: PrepaidExpenseAndOtherAssetsCurrent to label_PrepaidExpenseAndOtherAssetsCurrent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_PrepaidExpenseAndOtherAssetsCurrent_3" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_PrepaidExpenseAndOtherAssetsCurrent" xml:lang="en-US" id="label_PrepaidExpenseAndOtherAssetsCurrent_3">Prepaid expenses and other current assets (NPM restricted December 31, 2012 $485)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PrepaidExpenseAndOtherAssetsCurrent" xlink:to="label_PrepaidExpenseAndOtherAssetsCurrent_3" xlink:title="label: PrepaidExpenseAndOtherAssetsCurrent to label_PrepaidExpenseAndOtherAssetsCurrent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_PrepaidExpenseAndOtherAssetsCurrent_4" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_PrepaidExpenseAndOtherAssetsCurrent" xml:lang="en-US" id="label_PrepaidExpenseAndOtherAssetsCurrent_4">Prepaid expenses and other current assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PrepaidExpenseAndOtherAssetsCurrent" xlink:to="label_PrepaidExpenseAndOtherAssetsCurrent_4" xlink:title="label: PrepaidExpenseAndOtherAssetsCurrent to label_PrepaidExpenseAndOtherAssetsCurrent" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromConvertibleDebt" xlink:label="ProceedsFromConvertibleDebt" xlink:title="ProceedsFromConvertibleDebt" />
    <link:label xlink:type="resource" xlink:label="label_ProceedsFromConvertibleDebt" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ProceedsFromConvertibleDebt" xml:lang="en-US" id="label_ProceedsFromConvertibleDebt">Proceeds from Convertible Debt</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ProceedsFromConvertibleDebt" xlink:to="label_ProceedsFromConvertibleDebt" xlink:title="label: ProceedsFromConvertibleDebt to label_ProceedsFromConvertibleDebt" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ProceedsFromConvertibleDebt_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ProceedsFromConvertibleDebt" xml:lang="en-US" id="label_ProceedsFromConvertibleDebt_2">Proceeds from the issuance of convertible notes</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ProceedsFromConvertibleDebt" xlink:to="label_ProceedsFromConvertibleDebt_2" xlink:title="label: ProceedsFromConvertibleDebt to label_ProceedsFromConvertibleDebt" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" xlink:label="ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" xlink:title="ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" />
    <link:label xlink:type="resource" xlink:label="label_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" xml:lang="en-US" id="label_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock">Proceeds from the issuance of preferred stock subscription</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" xlink:to="label_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" xlink:title="label: ProceedsFromIssuanceOfPreferredStockAndPreferenceStock to label_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" xml:lang="en-US" id="label_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock_2">Proceeds from Issuance of Preferred Stock and Preference Stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" xlink:to="label_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock_2" xlink:title="label: ProceedsFromIssuanceOfPreferredStockAndPreferenceStock to label_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromIssuanceInitialPublicOffering" xlink:label="ProceedsFromIssuanceInitialPublicOffering" xlink:title="ProceedsFromIssuanceInitialPublicOffering" />
    <link:label xlink:type="resource" xlink:label="label_ProceedsFromIssuanceInitialPublicOffering" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ProceedsFromIssuanceInitialPublicOffering" xml:lang="en-US" id="label_ProceedsFromIssuanceInitialPublicOffering">Proceeds from Issuance Initial Public Offering</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ProceedsFromIssuanceInitialPublicOffering" xlink:to="label_ProceedsFromIssuanceInitialPublicOffering" xlink:title="label: ProceedsFromIssuanceInitialPublicOffering to label_ProceedsFromIssuanceInitialPublicOffering" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ProceedsFromIssuanceInitialPublicOffering_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ProceedsFromIssuanceInitialPublicOffering" xml:lang="en-US" id="label_ProceedsFromIssuanceInitialPublicOffering_2">Net proceeds from public offering</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ProceedsFromIssuanceInitialPublicOffering" xlink:to="label_ProceedsFromIssuanceInitialPublicOffering_2" xlink:title="label: ProceedsFromIssuanceInitialPublicOffering to label_ProceedsFromIssuanceInitialPublicOffering" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:label="ProceedsFromIssuanceOfCommonStock" xlink:title="ProceedsFromIssuanceOfCommonStock" />
    <link:label xlink:type="resource" xlink:label="label_ProceedsFromIssuanceOfCommonStock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ProceedsFromIssuanceOfCommonStock" xml:lang="en-US" id="label_ProceedsFromIssuanceOfCommonStock">Net proceeds from issuance of common stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ProceedsFromIssuanceOfCommonStock" xlink:to="label_ProceedsFromIssuanceOfCommonStock" xlink:title="label: ProceedsFromIssuanceOfCommonStock to label_ProceedsFromIssuanceOfCommonStock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ProceedsFromIssuanceOfCommonStock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ProceedsFromIssuanceOfCommonStock" xml:lang="en-US" id="label_ProceedsFromIssuanceOfCommonStock_2">Proceeds from Issuance of Common Stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ProceedsFromIssuanceOfCommonStock" xlink:to="label_ProceedsFromIssuanceOfCommonStock_2" xlink:title="label: ProceedsFromIssuanceOfCommonStock to label_ProceedsFromIssuanceOfCommonStock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="ProceedsFromStockOptionsExercised" xlink:title="ProceedsFromStockOptionsExercised" />
    <link:label xlink:type="resource" xlink:label="label_ProceedsFromStockOptionsExercised" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ProceedsFromStockOptionsExercised" xml:lang="en-US" id="label_ProceedsFromStockOptionsExercised">Proceeds from the exercise of stock options</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ProceedsFromStockOptionsExercised" xlink:to="label_ProceedsFromStockOptionsExercised" xlink:title="label: ProceedsFromStockOptionsExercised to label_ProceedsFromStockOptionsExercised" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ProceedsFromStockOptionsExercised_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ProceedsFromStockOptionsExercised" xml:lang="en-US" id="label_ProceedsFromStockOptionsExercised_2">Proceeds from Stock Options Exercised</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ProceedsFromStockOptionsExercised" xlink:to="label_ProceedsFromStockOptionsExercised_2" xlink:title="label: ProceedsFromStockOptionsExercised to label_ProceedsFromStockOptionsExercised" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:label="PropertyPlantAndEquipmentUsefulLife" xlink:title="PropertyPlantAndEquipmentUsefulLife" />
    <link:label xlink:type="resource" xlink:label="label_PropertyPlantAndEquipmentUsefulLife" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_PropertyPlantAndEquipmentUsefulLife" xml:lang="en-US" id="label_PropertyPlantAndEquipmentUsefulLife">Estimated useful life</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PropertyPlantAndEquipmentUsefulLife" xlink:to="label_PropertyPlantAndEquipmentUsefulLife" xlink:title="label: PropertyPlantAndEquipmentUsefulLife to label_PropertyPlantAndEquipmentUsefulLife" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_PropertyPlantAndEquipmentUsefulLife_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_PropertyPlantAndEquipmentUsefulLife" xml:lang="en-US" id="label_PropertyPlantAndEquipmentUsefulLife_2">Property, Plant and Equipment, Useful Life</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PropertyPlantAndEquipmentUsefulLife" xlink:to="label_PropertyPlantAndEquipmentUsefulLife_2" xlink:title="label: PropertyPlantAndEquipmentUsefulLife to label_PropertyPlantAndEquipmentUsefulLife" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="PropertyPlantAndEquipmentGross" xlink:title="PropertyPlantAndEquipmentGross" />
    <link:label xlink:type="resource" xlink:label="label_PropertyPlantAndEquipmentGross" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_PropertyPlantAndEquipmentGross" xml:lang="en-US" id="label_PropertyPlantAndEquipmentGross">Property, Plant and Equipment, Gross</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PropertyPlantAndEquipmentGross" xlink:to="label_PropertyPlantAndEquipmentGross" xlink:title="label: PropertyPlantAndEquipmentGross to label_PropertyPlantAndEquipmentGross" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_PropertyPlantAndEquipmentGross_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_PropertyPlantAndEquipmentGross" xml:lang="en-US" id="label_PropertyPlantAndEquipmentGross_2">Property and equipment, gross</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PropertyPlantAndEquipmentGross" xlink:to="label_PropertyPlantAndEquipmentGross_2" xlink:title="label: PropertyPlantAndEquipmentGross to label_PropertyPlantAndEquipmentGross" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:label="PropertyPlantAndEquipmentPolicyTextBlock" xlink:title="PropertyPlantAndEquipmentPolicyTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_PropertyPlantAndEquipmentPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_PropertyPlantAndEquipmentPolicyTextBlock" xml:lang="en-US" id="label_PropertyPlantAndEquipmentPolicyTextBlock">Property and Equipment, net</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PropertyPlantAndEquipmentPolicyTextBlock" xlink:to="label_PropertyPlantAndEquipmentPolicyTextBlock" xlink:title="label: PropertyPlantAndEquipmentPolicyTextBlock to label_PropertyPlantAndEquipmentPolicyTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_PropertyPlantAndEquipmentPolicyTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_PropertyPlantAndEquipmentPolicyTextBlock" xml:lang="en-US" id="label_PropertyPlantAndEquipmentPolicyTextBlock_2">Property, Plant and Equipment, Policy [Policy Text Block]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PropertyPlantAndEquipmentPolicyTextBlock" xlink:to="label_PropertyPlantAndEquipmentPolicyTextBlock_2" xlink:title="label: PropertyPlantAndEquipmentPolicyTextBlock to label_PropertyPlantAndEquipmentPolicyTextBlock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="PropertyPlantAndEquipmentNet" xlink:title="PropertyPlantAndEquipmentNet" />
    <link:label xlink:type="resource" xlink:label="label_PropertyPlantAndEquipmentNet" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:title="label_PropertyPlantAndEquipmentNet" xml:lang="en-US" id="label_PropertyPlantAndEquipmentNet">Property and equipment, net</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PropertyPlantAndEquipmentNet" xlink:to="label_PropertyPlantAndEquipmentNet" xlink:title="label: PropertyPlantAndEquipmentNet to label_PropertyPlantAndEquipmentNet" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_PropertyPlantAndEquipmentNet_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_PropertyPlantAndEquipmentNet" xml:lang="en-US" id="label_PropertyPlantAndEquipmentNet_2">Property, Plant and Equipment, Net</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PropertyPlantAndEquipmentNet" xlink:to="label_PropertyPlantAndEquipmentNet_2" xlink:title="label: PropertyPlantAndEquipmentNet to label_PropertyPlantAndEquipmentNet" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_PropertyPlantAndEquipmentNet_3" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_PropertyPlantAndEquipmentNet" xml:lang="en-US" id="label_PropertyPlantAndEquipmentNet_3">Property and equipment, net</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PropertyPlantAndEquipmentNet" xlink:to="label_PropertyPlantAndEquipmentNet_3" xlink:title="label: PropertyPlantAndEquipmentNet to label_PropertyPlantAndEquipmentNet" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentAbstract" xlink:label="PropertyPlantAndEquipmentAbstract" xlink:title="PropertyPlantAndEquipmentAbstract" />
    <link:label xlink:type="resource" xlink:label="label_PropertyPlantAndEquipmentAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_PropertyPlantAndEquipmentAbstract" xml:lang="en-US" id="label_PropertyPlantAndEquipmentAbstract">Property and Equipment, net</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PropertyPlantAndEquipmentAbstract" xlink:to="label_PropertyPlantAndEquipmentAbstract" xlink:title="label: PropertyPlantAndEquipmentAbstract to label_PropertyPlantAndEquipmentAbstract" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="PropertyPlantAndEquipmentTypeDomain" xlink:title="PropertyPlantAndEquipmentTypeDomain" />
    <link:label xlink:type="resource" xlink:label="label_PropertyPlantAndEquipmentTypeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_PropertyPlantAndEquipmentTypeDomain" xml:lang="en-US" id="label_PropertyPlantAndEquipmentTypeDomain">Property, Plant and Equipment, Type [Domain]</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="PropertyPlantAndEquipmentByTypeAxis" xlink:title="PropertyPlantAndEquipmentByTypeAxis" />
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    <link:label xlink:type="resource" xlink:label="label_PropertyPlantAndEquipmentDisclosureTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_PropertyPlantAndEquipmentDisclosureTextBlock" xml:lang="en-US" id="label_PropertyPlantAndEquipmentDisclosureTextBlock_2">Property, Plant and Equipment Disclosure [Text Block]</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="PropertyPlantAndEquipmentLineItems" xlink:title="PropertyPlantAndEquipmentLineItems" />
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PropertyPlantAndEquipmentLineItems" xlink:to="label_PropertyPlantAndEquipmentLineItems_2" xlink:title="label: PropertyPlantAndEquipmentLineItems to label_PropertyPlantAndEquipmentLineItems" use="optional" />
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="PropertyPlantAndEquipmentLineItems" xlink:to="label_PropertyPlantAndEquipmentLineItems_3" xlink:title="label: PropertyPlantAndEquipmentLineItems to label_PropertyPlantAndEquipmentLineItems" use="optional" />
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="QuarterlyFinancialInformationTextBlock" xlink:to="label_QuarterlyFinancialInformationTextBlock" xlink:title="label: QuarterlyFinancialInformationTextBlock to label_QuarterlyFinancialInformationTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_QuarterlyFinancialInformationTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_QuarterlyFinancialInformationTextBlock" xml:lang="en-US" id="label_QuarterlyFinancialInformationTextBlock_2">Quarterly Financial Information [Text Block]</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_QuarterlyFinancialInformationDisclosureAbstract" xlink:label="QuarterlyFinancialInformationDisclosureAbstract" xlink:title="QuarterlyFinancialInformationDisclosureAbstract" />
    <link:label xlink:type="resource" xlink:label="label_QuarterlyFinancialInformationDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_QuarterlyFinancialInformationDisclosureAbstract" xml:lang="en-US" id="label_QuarterlyFinancialInformationDisclosureAbstract">Selected Quarterly Financial Information (Unaudited)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="QuarterlyFinancialInformationDisclosureAbstract" xlink:to="label_QuarterlyFinancialInformationDisclosureAbstract" xlink:title="label: QuarterlyFinancialInformationDisclosureAbstract to label_QuarterlyFinancialInformationDisclosureAbstract" use="optional" />
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="RangeAxis" xlink:to="label_RangeAxis" xlink:title="label: RangeAxis to label_RangeAxis" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeMember" xlink:label="RangeMember" xlink:title="RangeMember" />
    <link:label xlink:type="resource" xlink:label="label_RangeMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_RangeMember" xml:lang="en-US" id="label_RangeMember">Range [Domain]</link:label>
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="RelatedPartyTransactionsDisclosureTextBlock" xlink:to="label_RelatedPartyTransactionsDisclosureTextBlock" xlink:title="label: RelatedPartyTransactionsDisclosureTextBlock to label_RelatedPartyTransactionsDisclosureTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_RelatedPartyTransactionsDisclosureTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_RelatedPartyTransactionsDisclosureTextBlock" xml:lang="en-US" id="label_RelatedPartyTransactionsDisclosureTextBlock_2">Related Party Transactions Disclosure [Text Block]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="RelatedPartyTransactionsDisclosureTextBlock" xlink:to="label_RelatedPartyTransactionsDisclosureTextBlock_2" xlink:title="label: RelatedPartyTransactionsDisclosureTextBlock to label_RelatedPartyTransactionsDisclosureTextBlock" use="optional" />
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    <link:label xlink:type="resource" xlink:label="label_ResearchAndDevelopmentExpense_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ResearchAndDevelopmentExpense" xml:lang="en-US" id="label_ResearchAndDevelopmentExpense_2">Research and Development Expense</link:label>
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ResearchAndDevelopmentExpenseMember" xlink:to="label_ResearchAndDevelopmentExpenseMember" xlink:title="label: ResearchAndDevelopmentExpenseMember to label_ResearchAndDevelopmentExpenseMember" use="optional" />
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    <link:label xlink:type="resource" xlink:label="label_RevenueRecognitionPolicyTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_RevenueRecognitionPolicyTextBlock" xml:lang="en-US" id="label_RevenueRecognitionPolicyTextBlock_2">Revenue Recognition, Policy [Policy Text Block]</link:label>
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    <link:label xlink:type="resource" xlink:label="label_RevenueRecognitionMilestoneMethodRevenueRecognized_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_RevenueRecognitionMilestoneMethodRevenueRecognized" xml:lang="en-US" id="label_RevenueRecognitionMilestoneMethodRevenueRecognized_2">Revenue Recognition, Milestone Method, Revenue Recognized</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RevenueRecognitionMilestoneMethodLineItems" xlink:label="RevenueRecognitionMilestoneMethodLineItems" xlink:title="RevenueRecognitionMilestoneMethodLineItems" />
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    <link:label xlink:type="resource" xlink:label="label_RevenueRecognitionMilestoneMethodLineItems_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_RevenueRecognitionMilestoneMethodLineItems" xml:lang="en-US" id="label_RevenueRecognitionMilestoneMethodLineItems_2">Revenue Recognition, Milestone Method [Line Items]</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RevenueRecognitionMilestoneMethodTable" xlink:label="RevenueRecognitionMilestoneMethodTable" xlink:title="RevenueRecognitionMilestoneMethodTable" />
    <link:label xlink:type="resource" xlink:label="label_RevenueRecognitionMilestoneMethodTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_RevenueRecognitionMilestoneMethodTable" xml:lang="en-US" id="label_RevenueRecognitionMilestoneMethodTable">Revenue Recognition, Milestone Method [Table]</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares" xlink:label="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares" xlink:title="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares" />
    <link:label xlink:type="resource" xlink:label="label_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:title="label_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares" xml:lang="en-US" id="label_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares">Unvested at the beginning of the period (in shares)</link:label>
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    <link:label xlink:type="resource" xlink:label="label_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares_2" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:title="label_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares" xml:lang="en-US" id="label_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares_2">Unvested at the end of the period (in shares)</link:label>
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    <link:label xlink:type="resource" xlink:label="label_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares_3" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares" xml:lang="en-US" id="label_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares_3">Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage" xlink:label="SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage" xlink:title="SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage" />
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    <link:label xlink:type="resource" xlink:label="label_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage" xml:lang="en-US" id="label_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_2">Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xlink:label="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xlink:title="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" />
    <link:label xlink:type="resource" xlink:label="label_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xml:lang="en-US" id="label_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1">Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value</link:label>
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    <link:label xlink:type="resource" xlink:label="label_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1_2" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:title="label_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xml:lang="en-US" id="label_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1_2">Options exercisable at the end of the period</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:label="SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:title="SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" />
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    <link:label xlink:type="resource" xlink:label="label_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent" xml:lang="en-US" id="label_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent">Purchase price of common stock (as a percent)</link:label>
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    <link:label xlink:type="resource" xlink:label="label_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xml:lang="en-US" id="label_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod">Expiration period</link:label>
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    <link:label xlink:type="resource" xlink:label="label_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xml:lang="en-US" id="label_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_2">Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period</link:label>
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ScheduleOfCondensedBalanceSheetTableTextBlock" xlink:to="label_ScheduleOfCondensedBalanceSheetTableTextBlock" xlink:title="label: ScheduleOfCondensedBalanceSheetTableTextBlock to label_ScheduleOfCondensedBalanceSheetTableTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ScheduleOfCondensedBalanceSheetTableTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ScheduleOfCondensedBalanceSheetTableTextBlock" xml:lang="en-US" id="label_ScheduleOfCondensedBalanceSheetTableTextBlock_2">Condensed Balance Sheet [Table Text Block]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ScheduleOfCondensedBalanceSheetTableTextBlock" xlink:to="label_ScheduleOfCondensedBalanceSheetTableTextBlock_2" xlink:title="label: ScheduleOfCondensedBalanceSheetTableTextBlock to label_ScheduleOfCondensedBalanceSheetTableTextBlock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:label="ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:title="ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xml:lang="en-US" id="label_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock">Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:to="label_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:title="label: ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock to label_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xml:lang="en-US" id="label_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_2">Schedule of reconciliation of income tax expense computed at the statutory federal income tax rate to income taxes</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:to="label_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_2" xlink:title="label: ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock to label_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:label="ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:title="ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xml:lang="en-US" id="label_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock">Schedule of significant components of the Company's deferred tax assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:to="label_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:title="label: ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock to label_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xml:lang="en-US" id="label_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_2">Schedule of Deferred Tax Assets and Liabilities [Table Text Block]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:to="label_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_2" xlink:title="label: ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock to label_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfAccruedLiabilitiesTableTextBlock" xlink:label="ScheduleOfAccruedLiabilitiesTableTextBlock" xlink:title="ScheduleOfAccruedLiabilitiesTableTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_ScheduleOfAccruedLiabilitiesTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ScheduleOfAccruedLiabilitiesTableTextBlock" xml:lang="en-US" id="label_ScheduleOfAccruedLiabilitiesTableTextBlock">Schedule of accrued expenses</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ScheduleOfAccruedLiabilitiesTableTextBlock" xlink:to="label_ScheduleOfAccruedLiabilitiesTableTextBlock" xlink:title="label: ScheduleOfAccruedLiabilitiesTableTextBlock to label_ScheduleOfAccruedLiabilitiesTableTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ScheduleOfAccruedLiabilitiesTableTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ScheduleOfAccruedLiabilitiesTableTextBlock" xml:lang="en-US" id="label_ScheduleOfAccruedLiabilitiesTableTextBlock_2">Schedule of Accrued Liabilities [Table Text Block]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ScheduleOfAccruedLiabilitiesTableTextBlock" xlink:to="label_ScheduleOfAccruedLiabilitiesTableTextBlock_2" xlink:title="label: ScheduleOfAccruedLiabilitiesTableTextBlock to label_ScheduleOfAccruedLiabilitiesTableTextBlock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock" xlink:label="ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock" xlink:title="ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock" xml:lang="en-US" id="label_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock">Schedule of minimum future rent payments under the lease agreement</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock" xlink:to="label_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock" xlink:title="label: ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock to label_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock" xml:lang="en-US" id="label_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock_2">Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock" xlink:to="label_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock_2" xlink:title="label: ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock to label_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfQuarterlyFinancialInformationTableTextBlock" xlink:label="ScheduleOfQuarterlyFinancialInformationTableTextBlock" xlink:title="ScheduleOfQuarterlyFinancialInformationTableTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_ScheduleOfQuarterlyFinancialInformationTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ScheduleOfQuarterlyFinancialInformationTableTextBlock" xml:lang="en-US" id="label_ScheduleOfQuarterlyFinancialInformationTableTextBlock">Schedule of selected quarterly financial information</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ScheduleOfQuarterlyFinancialInformationTableTextBlock" xlink:to="label_ScheduleOfQuarterlyFinancialInformationTableTextBlock" xlink:title="label: ScheduleOfQuarterlyFinancialInformationTableTextBlock to label_ScheduleOfQuarterlyFinancialInformationTableTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ScheduleOfQuarterlyFinancialInformationTableTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ScheduleOfQuarterlyFinancialInformationTableTextBlock" xml:lang="en-US" id="label_ScheduleOfQuarterlyFinancialInformationTableTextBlock_2">Schedule of Quarterly Financial Information [Table Text Block]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ScheduleOfQuarterlyFinancialInformationTableTextBlock" xlink:to="label_ScheduleOfQuarterlyFinancialInformationTableTextBlock_2" xlink:title="label: ScheduleOfQuarterlyFinancialInformationTableTextBlock to label_ScheduleOfQuarterlyFinancialInformationTableTextBlock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" xlink:label="ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" xlink:title="ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" />
    <link:label xlink:type="resource" xlink:label="label_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" xml:lang="en-US" id="label_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable">Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" xlink:to="label_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" xlink:title="label: ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable to label_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock" xlink:label="ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock" xlink:title="ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock" xml:lang="en-US" id="label_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock">Schedule of total stock-based compensation expense recognized in connection with all share-based payment awards</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock" xlink:to="label_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock" xlink:title="label: ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock to label_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock" xml:lang="en-US" id="label_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock_2">Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock" xlink:to="label_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock_2" xlink:title="label: ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock to label_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="ScheduleOfPropertyPlantAndEquipmentTable" xlink:title="ScheduleOfPropertyPlantAndEquipmentTable" />
    <link:label xlink:type="resource" xlink:label="label_ScheduleOfPropertyPlantAndEquipmentTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ScheduleOfPropertyPlantAndEquipmentTable" xml:lang="en-US" id="label_ScheduleOfPropertyPlantAndEquipmentTable">Property, Plant and Equipment [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ScheduleOfPropertyPlantAndEquipmentTable" xlink:to="label_ScheduleOfPropertyPlantAndEquipmentTable" xlink:title="label: ScheduleOfPropertyPlantAndEquipmentTable to label_ScheduleOfPropertyPlantAndEquipmentTable" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:title="ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" />
    <link:label xlink:type="resource" xlink:label="label_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xml:lang="en-US" id="label_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable">Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="label_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:title="label: ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable to label_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfStockByClassTable" xlink:label="ScheduleOfStockByClassTable" xlink:title="ScheduleOfStockByClassTable" />
    <link:label xlink:type="resource" xlink:label="label_ScheduleOfStockByClassTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ScheduleOfStockByClassTable" xml:lang="en-US" id="label_ScheduleOfStockByClassTable">Schedule of Stock by Class [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ScheduleOfStockByClassTable" xlink:to="label_ScheduleOfStockByClassTable" xlink:title="label: ScheduleOfStockByClassTable to label_ScheduleOfStockByClassTable" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SecurityDeposit" xlink:label="SecurityDeposit" xlink:title="SecurityDeposit" />
    <link:label xlink:type="resource" xlink:label="label_SecurityDeposit" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SecurityDeposit" xml:lang="en-US" id="label_SecurityDeposit">Security deposit in the form of a letter of credit</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SecurityDeposit" xlink:to="label_SecurityDeposit" xlink:title="label: SecurityDeposit to label_SecurityDeposit" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SecurityDeposit_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SecurityDeposit" xml:lang="en-US" id="label_SecurityDeposit_2">Security Deposit</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SecurityDeposit" xlink:to="label_SecurityDeposit_2" xlink:title="label: SecurityDeposit to label_SecurityDeposit" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SegmentReportingPolicyPolicyTextBlock" xlink:label="SegmentReportingPolicyPolicyTextBlock" xlink:title="SegmentReportingPolicyPolicyTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_SegmentReportingPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SegmentReportingPolicyPolicyTextBlock" xml:lang="en-US" id="label_SegmentReportingPolicyPolicyTextBlock">Segment Information</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SegmentReportingPolicyPolicyTextBlock" xlink:to="label_SegmentReportingPolicyPolicyTextBlock" xlink:title="label: SegmentReportingPolicyPolicyTextBlock to label_SegmentReportingPolicyPolicyTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SegmentReportingPolicyPolicyTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SegmentReportingPolicyPolicyTextBlock" xml:lang="en-US" id="label_SegmentReportingPolicyPolicyTextBlock_2">Segment Reporting, Policy [Policy Text Block]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SegmentReportingPolicyPolicyTextBlock" xlink:to="label_SegmentReportingPolicyPolicyTextBlock_2" xlink:title="label: SegmentReportingPolicyPolicyTextBlock to label_SegmentReportingPolicyPolicyTextBlock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward">Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_2">Shares</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_2" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward">Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue">Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value</link:label>
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    <link:label xlink:type="resource" xlink:label="label_SharePrice_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SharePrice" xml:lang="en-US" id="label_SharePrice_2">Share Price</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SharePrice" xlink:to="label_SharePrice_2" xlink:title="label: SharePrice to label_SharePrice" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:label="ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:title="ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xml:lang="en-US" id="label_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice">Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:to="label_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:title="label: ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice to label_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" use="optional" />
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageVolatilityRate" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageVolatilityRate" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageVolatilityRate" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageVolatilityRate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageVolatilityRate" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageVolatilityRate">Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Weighted Average Volatility Rate</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageVolatilityRate" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageVolatilityRate" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageVolatilityRate to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageVolatilityRate" use="optional" />
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice">Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" use="optional" />
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" />
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue">Aggregate fair value of restricted stock awards vested</link:label>
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    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_2">Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_2" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod">Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" use="optional" />
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" />
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    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_2">Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" />
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    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_3" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_3">Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber">Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber_2" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber_2">Options vested or expected to vest at the end of the period (in shares)</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue">Outstanding at the end of the period</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_2">Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_2" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward">Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_2">Shares</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_2" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:title="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xml:lang="en-US" id="label_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain">Equity Award [Domain]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="label_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:title="label: ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain to label_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice">Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice_2" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice_2">Options vested or expected to vest at the end of the period (in dollars per share)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice_2" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue">Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue_2" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:title="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue" xml:lang="en-US" id="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue_2">Options vested or expected to vest at the end of the period</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue" xlink:to="label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue_2" xlink:title="label: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue to label_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharesIssued" xlink:label="SharesIssued" xlink:title="SharesIssued" />
    <link:label xlink:type="resource" xlink:label="label_SharesIssued" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SharesIssued" xml:lang="en-US" id="label_SharesIssued">Shares, Issued</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SharesIssued" xlink:to="label_SharesIssued" xlink:title="label: SharesIssued to label_SharesIssued" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SharesIssued_2" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:title="label_SharesIssued" xml:lang="en-US" id="label_SharesIssued_2">Balance (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SharesIssued" xlink:to="label_SharesIssued_2" xlink:title="label: SharesIssued to label_SharesIssued" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SharesIssued_3" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:title="label_SharesIssued" xml:lang="en-US" id="label_SharesIssued_3">Balance (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SharesIssued" xlink:to="label_SharesIssued_3" xlink:title="label: SharesIssued to label_SharesIssued" use="optional" />
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    <link:label xlink:type="resource" xlink:label="label_SignificantAccountingPoliciesTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SignificantAccountingPoliciesTextBlock" xml:lang="en-US" id="label_SignificantAccountingPoliciesTextBlock">Summary of Significant Accounting Policies</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SignificantAccountingPoliciesTextBlock" xlink:to="label_SignificantAccountingPoliciesTextBlock" xlink:title="label: SignificantAccountingPoliciesTextBlock to label_SignificantAccountingPoliciesTextBlock" use="optional" />
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    <link:label xlink:type="resource" xlink:label="label_StateAndLocalJurisdictionMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_StateAndLocalJurisdictionMember" xml:lang="en-US" id="label_StateAndLocalJurisdictionMember">U.S. state</link:label>
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StateAndLocalJurisdictionMember" xlink:to="label_StateAndLocalJurisdictionMember_3" xlink:title="label: StateAndLocalJurisdictionMember to label_StateAndLocalJurisdictionMember" use="optional" />
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    <link:label xlink:type="resource" xlink:label="label_StatementLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_StatementLineItems" xml:lang="en-US" id="label_StatementLineItems">Statement</link:label>
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    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodValueIssuedForServices_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_StockIssuedDuringPeriodValueIssuedForServices" xml:lang="en-US" id="label_StockIssuedDuringPeriodValueIssuedForServices_2">Aggregate cash consideration for number of shares of common stock sold in connection with service contract</link:label>
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodSharesNewIssues" xlink:to="label_StockIssuedDuringPeriodSharesNewIssues" xlink:title="label: StockIssuedDuringPeriodSharesNewIssues to label_StockIssuedDuringPeriodSharesNewIssues" use="optional" />
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    <link:label xlink:type="resource" xlink:label="label_StockOptionMember_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_StockOptionMember" xml:lang="en-US" id="label_StockOptionMember_2">Equity Option [Member]</link:label>
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    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" xml:lang="en-US" id="label_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_2">Stock Issued During Period, Shares, Conversion of Convertible Securities</link:label>
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    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_4" xlink:role="http://www.xbrl.org/2003/role/positiveLabel" xlink:title="label_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" xml:lang="en-US" id="label_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_4">Number of shares of stock issued upon automatic conversion of outstanding convertible securities</link:label>
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    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodValueNewIssues" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_StockIssuedDuringPeriodValueNewIssues" xml:lang="en-US" id="label_StockIssuedDuringPeriodValueNewIssues">Aggregate cash consideration for number of shares of common stock sold</link:label>
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockIssuedDuringPeriodValueNewIssues" xlink:to="label_StockIssuedDuringPeriodValueNewIssues_2" xlink:title="label: StockIssuedDuringPeriodValueNewIssues to label_StockIssuedDuringPeriodValueNewIssues" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockIssuedDuringPeriodValueNewIssues_3" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_StockIssuedDuringPeriodValueNewIssues" xml:lang="en-US" id="label_StockIssuedDuringPeriodValueNewIssues_3">Initial public offering, net of issuance costs of $3,207</link:label>
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    <link:label xlink:type="resource" xlink:label="label_StockholdersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_StockholdersEquityAbstract" xml:lang="en-US" id="label_StockholdersEquityAbstract">Stockholders' equity</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="StockholdersEquity" xlink:title="StockholdersEquity" />
    <link:label xlink:type="resource" xlink:label="label_StockholdersEquity" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:title="label_StockholdersEquity" xml:lang="en-US" id="label_StockholdersEquity">Total stockholders' equity</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockholdersEquity" xlink:to="label_StockholdersEquity" xlink:title="label: StockholdersEquity to label_StockholdersEquity" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_StockholdersEquity_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_StockholdersEquity" xml:lang="en-US" id="label_StockholdersEquity_2">Stockholders' Equity Attributable to Parent</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockholdersEquity" xlink:to="label_StockholdersEquity_2" xlink:title="label: StockholdersEquity to label_StockholdersEquity" use="optional" />
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="StockholdersEquity" xlink:to="label_StockholdersEquity_3" xlink:title="label: StockholdersEquity to label_StockholdersEquity" use="optional" />
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    <link:label xlink:type="resource" xlink:label="label_StockholdersEquityNoteAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_StockholdersEquityNoteAbstract" xml:lang="en-US" id="label_StockholdersEquityNoteAbstract">Stockholders' Equity</link:label>
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    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:label="StockholdersEquityNoteDisclosureTextBlock" xlink:title="StockholdersEquityNoteDisclosureTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_StockholdersEquityNoteDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_StockholdersEquityNoteDisclosureTextBlock" xml:lang="en-US" id="label_StockholdersEquityNoteDisclosureTextBlock">Stockholders' Equity</link:label>
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    <link:label xlink:type="resource" xlink:label="label_SubsequentEventLineItems_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SubsequentEventLineItems" xml:lang="en-US" id="label_SubsequentEventLineItems_2">Subsequent Events</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SubsequentEventLineItems" xlink:to="label_SubsequentEventLineItems_2" xlink:title="label: SubsequentEventLineItems to label_SubsequentEventLineItems" use="optional" />
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    <link:label xlink:type="resource" xlink:label="label_SubsequentEventsPolicyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SubsequentEventsPolicyPolicyTextBlock" xml:lang="en-US" id="label_SubsequentEventsPolicyPolicyTextBlock">Subsequent Events</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SubsequentEventsPolicyPolicyTextBlock" xlink:to="label_SubsequentEventsPolicyPolicyTextBlock" xlink:title="label: SubsequentEventsPolicyPolicyTextBlock to label_SubsequentEventsPolicyPolicyTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SubsequentEventsPolicyPolicyTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SubsequentEventsPolicyPolicyTextBlock" xml:lang="en-US" id="label_SubsequentEventsPolicyPolicyTextBlock_2">Subsequent Events, Policy [Policy Text Block]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SubsequentEventsPolicyPolicyTextBlock" xlink:to="label_SubsequentEventsPolicyPolicyTextBlock_2" xlink:title="label: SubsequentEventsPolicyPolicyTextBlock to label_SubsequentEventsPolicyPolicyTextBlock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="SubsequentEventMember" xlink:title="SubsequentEventMember" />
    <link:label xlink:type="resource" xlink:label="label_SubsequentEventMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SubsequentEventMember" xml:lang="en-US" id="label_SubsequentEventMember">Subsequent Event [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SubsequentEventMember" xlink:to="label_SubsequentEventMember" xlink:title="label: SubsequentEventMember to label_SubsequentEventMember" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_SubsequentEventMember_2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_SubsequentEventMember" xml:lang="en-US" id="label_SubsequentEventMember_2">Subsequent events</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SubsequentEventMember" xlink:to="label_SubsequentEventMember_2" xlink:title="label: SubsequentEventMember to label_SubsequentEventMember" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="SubsequentEventTypeDomain" xlink:title="SubsequentEventTypeDomain" />
    <link:label xlink:type="resource" xlink:label="label_SubsequentEventTypeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SubsequentEventTypeDomain" xml:lang="en-US" id="label_SubsequentEventTypeDomain">Subsequent Event Type [Domain]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SubsequentEventTypeDomain" xlink:to="label_SubsequentEventTypeDomain" xlink:title="label: SubsequentEventTypeDomain to label_SubsequentEventTypeDomain" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="SubsequentEventTypeAxis" xlink:title="SubsequentEventTypeAxis" />
    <link:label xlink:type="resource" xlink:label="label_SubsequentEventTypeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_SubsequentEventTypeAxis" xml:lang="en-US" id="label_SubsequentEventTypeAxis">Subsequent Event Type [Axis]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="SubsequentEventTypeAxis" xlink:to="label_SubsequentEventTypeAxis" xlink:title="label: SubsequentEventTypeAxis to label_SubsequentEventTypeAxis" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TaxCreditCarryforwardAmount" xlink:label="TaxCreditCarryforwardAmount" xlink:title="TaxCreditCarryforwardAmount" />
    <link:label xlink:type="resource" xlink:label="label_TaxCreditCarryforwardAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_TaxCreditCarryforwardAmount" xml:lang="en-US" id="label_TaxCreditCarryforwardAmount">Tax credit carryforwards</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TaxCreditCarryforwardAmount" xlink:to="label_TaxCreditCarryforwardAmount" xlink:title="label: TaxCreditCarryforwardAmount to label_TaxCreditCarryforwardAmount" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_TaxCreditCarryforwardAmount_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_TaxCreditCarryforwardAmount" xml:lang="en-US" id="label_TaxCreditCarryforwardAmount_2">Tax Credit Carryforward, Amount</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TaxCreditCarryforwardAmount" xlink:to="label_TaxCreditCarryforwardAmount_2" xlink:title="label: TaxCreditCarryforwardAmount to label_TaxCreditCarryforwardAmount" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TaxCreditCarryforwardNameDomain" xlink:label="TaxCreditCarryforwardNameDomain" xlink:title="TaxCreditCarryforwardNameDomain" />
    <link:label xlink:type="resource" xlink:label="label_TaxCreditCarryforwardNameDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_TaxCreditCarryforwardNameDomain" xml:lang="en-US" id="label_TaxCreditCarryforwardNameDomain">Tax Credit Carryforward, Name [Domain]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TaxCreditCarryforwardNameDomain" xlink:to="label_TaxCreditCarryforwardNameDomain" xlink:title="label: TaxCreditCarryforwardNameDomain to label_TaxCreditCarryforwardNameDomain" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TaxCreditCarryforwardLineItems" xlink:label="TaxCreditCarryforwardLineItems" xlink:title="TaxCreditCarryforwardLineItems" />
    <link:label xlink:type="resource" xlink:label="label_TaxCreditCarryforwardLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_TaxCreditCarryforwardLineItems" xml:lang="en-US" id="label_TaxCreditCarryforwardLineItems">Income Taxes</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TaxCreditCarryforwardLineItems" xlink:to="label_TaxCreditCarryforwardLineItems" xlink:title="label: TaxCreditCarryforwardLineItems to label_TaxCreditCarryforwardLineItems" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_TaxCreditCarryforwardLineItems_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_TaxCreditCarryforwardLineItems" xml:lang="en-US" id="label_TaxCreditCarryforwardLineItems_2">Tax Credit Carryforward [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TaxCreditCarryforwardLineItems" xlink:to="label_TaxCreditCarryforwardLineItems_2" xlink:title="label: TaxCreditCarryforwardLineItems to label_TaxCreditCarryforwardLineItems" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TaxCreditCarryforwardTable" xlink:label="TaxCreditCarryforwardTable" xlink:title="TaxCreditCarryforwardTable" />
    <link:label xlink:type="resource" xlink:label="label_TaxCreditCarryforwardTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_TaxCreditCarryforwardTable" xml:lang="en-US" id="label_TaxCreditCarryforwardTable">Tax Credit Carryforward [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TaxCreditCarryforwardTable" xlink:to="label_TaxCreditCarryforwardTable" xlink:title="label: TaxCreditCarryforwardTable to label_TaxCreditCarryforwardTable" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TaxCreditCarryforwardAxis" xlink:label="TaxCreditCarryforwardAxis" xlink:title="TaxCreditCarryforwardAxis" />
    <link:label xlink:type="resource" xlink:label="label_TaxCreditCarryforwardAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_TaxCreditCarryforwardAxis" xml:lang="en-US" id="label_TaxCreditCarryforwardAxis">Tax Credit Carryforward [Axis]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TaxCreditCarryforwardAxis" xlink:to="label_TaxCreditCarryforwardAxis" xlink:title="label: TaxCreditCarryforwardAxis to label_TaxCreditCarryforwardAxis" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TemporaryEquitySharesOutstanding" xlink:label="TemporaryEquitySharesOutstanding" xlink:title="TemporaryEquitySharesOutstanding" />
    <link:label xlink:type="resource" xlink:label="label_TemporaryEquitySharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_TemporaryEquitySharesOutstanding" xml:lang="en-US" id="label_TemporaryEquitySharesOutstanding">Convertible preferred stock, outstanding shares</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TemporaryEquitySharesOutstanding" xlink:to="label_TemporaryEquitySharesOutstanding" xlink:title="label: TemporaryEquitySharesOutstanding to label_TemporaryEquitySharesOutstanding" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_TemporaryEquitySharesOutstanding_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_TemporaryEquitySharesOutstanding" xml:lang="en-US" id="label_TemporaryEquitySharesOutstanding_2">Temporary Equity, Shares Outstanding</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TemporaryEquitySharesOutstanding" xlink:to="label_TemporaryEquitySharesOutstanding_2" xlink:title="label: TemporaryEquitySharesOutstanding to label_TemporaryEquitySharesOutstanding" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_TemporaryEquitySharesOutstanding_3" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:title="label_TemporaryEquitySharesOutstanding" xml:lang="en-US" id="label_TemporaryEquitySharesOutstanding_3">Preferred stock, outstanding shares</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TemporaryEquitySharesOutstanding" xlink:to="label_TemporaryEquitySharesOutstanding_3" xlink:title="label: TemporaryEquitySharesOutstanding to label_TemporaryEquitySharesOutstanding" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TemporaryEquityParOrStatedValuePerShare" xlink:label="TemporaryEquityParOrStatedValuePerShare" xlink:title="TemporaryEquityParOrStatedValuePerShare" />
    <link:label xlink:type="resource" xlink:label="label_TemporaryEquityParOrStatedValuePerShare" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_TemporaryEquityParOrStatedValuePerShare" xml:lang="en-US" id="label_TemporaryEquityParOrStatedValuePerShare">Convertible preferred stock, par value (in dollars per share)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TemporaryEquityParOrStatedValuePerShare" xlink:to="label_TemporaryEquityParOrStatedValuePerShare" xlink:title="label: TemporaryEquityParOrStatedValuePerShare to label_TemporaryEquityParOrStatedValuePerShare" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_TemporaryEquityParOrStatedValuePerShare_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_TemporaryEquityParOrStatedValuePerShare" xml:lang="en-US" id="label_TemporaryEquityParOrStatedValuePerShare_2">Temporary Equity, Par or Stated Value Per Share</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TemporaryEquityParOrStatedValuePerShare" xlink:to="label_TemporaryEquityParOrStatedValuePerShare_2" xlink:title="label: TemporaryEquityParOrStatedValuePerShare to label_TemporaryEquityParOrStatedValuePerShare" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TemporaryEquityCarryingAmountAttributableToParent" xlink:label="TemporaryEquityCarryingAmountAttributableToParent" xlink:title="TemporaryEquityCarryingAmountAttributableToParent" />
    <link:label xlink:type="resource" xlink:label="label_TemporaryEquityCarryingAmountAttributableToParent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_TemporaryEquityCarryingAmountAttributableToParent" xml:lang="en-US" id="label_TemporaryEquityCarryingAmountAttributableToParent">Convertible preferred stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TemporaryEquityCarryingAmountAttributableToParent" xlink:to="label_TemporaryEquityCarryingAmountAttributableToParent" xlink:title="label: TemporaryEquityCarryingAmountAttributableToParent to label_TemporaryEquityCarryingAmountAttributableToParent" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_TemporaryEquityCarryingAmountAttributableToParent_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_TemporaryEquityCarryingAmountAttributableToParent" xml:lang="en-US" id="label_TemporaryEquityCarryingAmountAttributableToParent_2">Temporary Equity, Carrying Amount, Attributable to Parent</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TemporaryEquityCarryingAmountAttributableToParent" xlink:to="label_TemporaryEquityCarryingAmountAttributableToParent_2" xlink:title="label: TemporaryEquityCarryingAmountAttributableToParent to label_TemporaryEquityCarryingAmountAttributableToParent" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TemporaryEquityTableTextBlock" xlink:label="TemporaryEquityTableTextBlock" xlink:title="TemporaryEquityTableTextBlock" />
    <link:label xlink:type="resource" xlink:label="label_TemporaryEquityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_TemporaryEquityTableTextBlock" xml:lang="en-US" id="label_TemporaryEquityTableTextBlock">Schedule of convertible preferred stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TemporaryEquityTableTextBlock" xlink:to="label_TemporaryEquityTableTextBlock" xlink:title="label: TemporaryEquityTableTextBlock to label_TemporaryEquityTableTextBlock" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_TemporaryEquityTableTextBlock_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_TemporaryEquityTableTextBlock" xml:lang="en-US" id="label_TemporaryEquityTableTextBlock_2">Temporary Equity [Table Text Block]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TemporaryEquityTableTextBlock" xlink:to="label_TemporaryEquityTableTextBlock_2" xlink:title="label: TemporaryEquityTableTextBlock to label_TemporaryEquityTableTextBlock" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TemporaryEquitySharesAuthorized" xlink:label="TemporaryEquitySharesAuthorized" xlink:title="TemporaryEquitySharesAuthorized" />
    <link:label xlink:type="resource" xlink:label="label_TemporaryEquitySharesAuthorized" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_TemporaryEquitySharesAuthorized" xml:lang="en-US" id="label_TemporaryEquitySharesAuthorized">Convertible preferred stock, authorized shares</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TemporaryEquitySharesAuthorized" xlink:to="label_TemporaryEquitySharesAuthorized" xlink:title="label: TemporaryEquitySharesAuthorized to label_TemporaryEquitySharesAuthorized" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_TemporaryEquitySharesAuthorized_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_TemporaryEquitySharesAuthorized" xml:lang="en-US" id="label_TemporaryEquitySharesAuthorized_2">Temporary Equity, Shares Authorized</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TemporaryEquitySharesAuthorized" xlink:to="label_TemporaryEquitySharesAuthorized_2" xlink:title="label: TemporaryEquitySharesAuthorized to label_TemporaryEquitySharesAuthorized" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TemporaryEquitySharesIssued" xlink:label="TemporaryEquitySharesIssued" xlink:title="TemporaryEquitySharesIssued" />
    <link:label xlink:type="resource" xlink:label="label_TemporaryEquitySharesIssued" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:title="label_TemporaryEquitySharesIssued" xml:lang="en-US" id="label_TemporaryEquitySharesIssued">Convertible preferred stock, issued shares</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TemporaryEquitySharesIssued" xlink:to="label_TemporaryEquitySharesIssued" xlink:title="label: TemporaryEquitySharesIssued to label_TemporaryEquitySharesIssued" use="optional" />
    <link:label xlink:type="resource" xlink:label="label_TemporaryEquitySharesIssued_2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_TemporaryEquitySharesIssued" xml:lang="en-US" id="label_TemporaryEquitySharesIssued_2">Temporary Equity, Shares Issued</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TemporaryEquitySharesIssued" xlink:to="label_TemporaryEquitySharesIssued_2" xlink:title="label: TemporaryEquitySharesIssued to label_TemporaryEquitySharesIssued" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TitleOfIndividualAxis" xlink:label="TitleOfIndividualAxis" xlink:title="TitleOfIndividualAxis" />
    <link:label xlink:type="resource" xlink:label="label_TitleOfIndividualAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_TitleOfIndividualAxis" xml:lang="en-US" id="label_TitleOfIndividualAxis">Title of Individual [Axis]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TitleOfIndividualAxis" xlink:to="label_TitleOfIndividualAxis" xlink:title="label: TitleOfIndividualAxis to label_TitleOfIndividualAxis" use="optional" />
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    <link:label xlink:type="resource" xlink:label="label_TitleOfIndividualWithRelationshipToEntityDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_TitleOfIndividualWithRelationshipToEntityDomain" xml:lang="en-US" id="label_TitleOfIndividualWithRelationshipToEntityDomain">Relationship to Entity [Domain]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TitleOfIndividualWithRelationshipToEntityDomain" xlink:to="label_TitleOfIndividualWithRelationshipToEntityDomain" xlink:title="label: TitleOfIndividualWithRelationshipToEntityDomain to label_TitleOfIndividualWithRelationshipToEntityDomain" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TypeOfArrangementAxis" xlink:label="TypeOfArrangementAxis" xlink:title="TypeOfArrangementAxis" />
    <link:label xlink:type="resource" xlink:label="label_TypeOfArrangementAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:title="label_TypeOfArrangementAxis" xml:lang="en-US" id="label_TypeOfArrangementAxis">Type of Arrangement and Non-arrangement Transactions [Axis]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="TypeOfArrangementAxis" xlink:to="label_TypeOfArrangementAxis" xlink:title="label: TypeOfArrangementAxis to label_TypeOfArrangementAxis" use="optional" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense" xlink:label="UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense" xlink:title="UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense" />
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