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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="lab_us-gaap_CashAndCashEquivalentsAtCarryingValue" xml:lang="en-US">CASH &amp; CASH EQUIVALENTS, BEGINNING BALANCE</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="lab_us-gaap_CashAndCashEquivalentsAtCarryingValue" xml:lang="en-US">CASH &amp; CASH EQUIVALENTS, ENDING BALANCE</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:to="lab_us-gaap_CashAndCashEquivalentsAtCarryingValue" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_AccountsReceivableNetCurrent" xml:lang="en-US">Accounts Receivable, Net, Current, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_AccountsReceivableNetCurrent" xml:lang="en-US">Accounts receivable, net</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccountsReceivableNetCurrent" xlink:to="lab_us-gaap_AccountsReceivableNetCurrent" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PrepaidExpenseCurrent" xlink:label="loc_us-gaap_PrepaidExpenseCurrent" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_PrepaidExpenseCurrent" xml:lang="en-US">Prepaid Expense, Current, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_PrepaidExpenseCurrent" xml:lang="en-US">Prepaid expense</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="lab_us-gaap_PrepaidExpenseCurrent" xml:lang="en-US">Prepaid expense</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PrepaidExpenseCurrent" xlink:to="lab_us-gaap_PrepaidExpenseCurrent" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_InventoryNet" xlink:label="loc_us-gaap_InventoryNet" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_InventoryNet" xml:lang="en-US">Inventory, Net</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_InventoryNet" xml:lang="en-US">Inventory, net</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InventoryNet" xlink:to="lab_us-gaap_InventoryNet" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentNet" xml:lang="en-US">Property, Plant and Equipment, Net</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentNet" xml:lang="en-US">Furniture and equipment, net</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentNet" xml:lang="en-US">Furniture and equipment, net</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNet" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentNet" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsNet" xml:lang="en-US">Finite-Lived Intangible Assets, Net, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsNet" xml:lang="en-US">Intangible assets, net</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsNet" xml:lang="en-US">Intangible assets, net</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsNet" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DeferredFinanceCostsNoncurrentNet" xlink:label="loc_us-gaap_DeferredFinanceCostsNoncurrentNet" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_DeferredFinanceCostsNoncurrentNet" xml:lang="en-US">Deferred Finance Costs, Noncurrent, Net</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_DeferredFinanceCostsNoncurrentNet" xml:lang="en-US">Deferred financing costs</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredFinanceCostsNoncurrentNet" xlink:to="lab_us-gaap_DeferredFinanceCostsNoncurrentNet" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SecurityDeposit" xlink:label="loc_us-gaap_SecurityDeposit" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SecurityDeposit" xml:lang="en-US">Security Deposit</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_SecurityDeposit" xml:lang="en-US">Security deposit</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_SecurityDeposit" xml:lang="en-US">Security Deposit</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SecurityDeposit" xlink:to="lab_us-gaap_SecurityDeposit" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_Assets" xlink:label="loc_us-gaap_Assets" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_Assets" xml:lang="en-US">Assets, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="lab_us-gaap_Assets" xml:lang="en-US">Total assets</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_Assets" xlink:to="lab_us-gaap_Assets" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNetAbstract" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNetAbstract" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentNetAbstract" xml:lang="en-US">Property, Plant and Equipment, Net [Abstract]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentNetAbstract" xml:lang="en-US">Fixed assets</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNetAbstract" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentNetAbstract" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xml:lang="en-US">Liabilities and Equity [Abstract]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xml:lang="en-US">Liabilities and Stockholders&#39; Equity</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_LiabilitiesCurrentAbstract" xml:lang="en-US">Liabilities, Current [Abstract]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_LiabilitiesCurrentAbstract" xml:lang="en-US">Current liabilities</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract" xlink:to="lab_us-gaap_LiabilitiesCurrentAbstract" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="loc_us-gaap_AccountsPayableCurrent" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_AccountsPayableCurrent" xml:lang="en-US">Accounts Payable, Current</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_AccountsPayableCurrent" xml:lang="en-US">Accounts payable</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccountsPayableCurrent" xlink:to="lab_us-gaap_AccountsPayableCurrent" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_AccruedLiabilitiesCurrent" xml:lang="en-US">Accrued Liabilities, Current</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_AccruedLiabilitiesCurrent" xml:lang="en-US">Accrued expenses</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccruedLiabilitiesCurrent" xlink:to="lab_us-gaap_AccruedLiabilitiesCurrent" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DeferredRentCreditCurrent" xlink:label="loc_us-gaap_DeferredRentCreditCurrent" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_DeferredRentCreditCurrent" xml:lang="en-US">Deferred Rent Credit, Current</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_DeferredRentCreditCurrent" xml:lang="en-US">Deferred rent</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredRentCreditCurrent" xlink:to="lab_us-gaap_DeferredRentCreditCurrent" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:label="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_EmployeeRelatedLiabilitiesCurrent" xml:lang="en-US">Employee-related Liabilities, Current</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_EmployeeRelatedLiabilitiesCurrent" xml:lang="en-US">Payroll liabilities</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="lab_us-gaap_EmployeeRelatedLiabilitiesCurrent" xml:lang="en-US">Payroll liabilities</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:to="lab_us-gaap_EmployeeRelatedLiabilitiesCurrent" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LossContingencyAccrualCarryingValueCurrent" xlink:label="loc_us-gaap_LossContingencyAccrualCarryingValueCurrent" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_LossContingencyAccrualCarryingValueCurrent" xml:lang="en-US">Loss Contingency, Accrual, Current</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_LossContingencyAccrualCarryingValueCurrent" xml:lang="en-US">Product recall liabilities</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LossContingencyAccrualCarryingValueCurrent" xlink:to="lab_us-gaap_LossContingencyAccrualCarryingValueCurrent" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherLiabilitiesCurrent" xlink:label="loc_us-gaap_OtherLiabilitiesCurrent" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_OtherLiabilitiesCurrent" xml:lang="en-US">Other Liabilities, Current</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_OtherLiabilitiesCurrent" xml:lang="en-US">Other current liabilities</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherLiabilitiesCurrent" xlink:to="lab_us-gaap_OtherLiabilitiesCurrent" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="loc_us-gaap_LiabilitiesCurrent" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_LiabilitiesCurrent" xml:lang="en-US">Liabilities, Current, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="lab_us-gaap_LiabilitiesCurrent" xml:lang="en-US">Total current liabilities</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesCurrent" xlink:to="lab_us-gaap_LiabilitiesCurrent" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockholdersEquityAbstract" xlink:label="loc_us-gaap_StockholdersEquityAbstract" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_StockholdersEquityAbstract" xml:lang="en-US">Stockholders&#39; Equity Attributable To Parent [Abstract]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_StockholdersEquityAbstract" xml:lang="en-US">Stockholders&#39; Equity</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockholdersEquityAbstract" xlink:to="lab_us-gaap_StockholdersEquityAbstract" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PreferredStockValue" xlink:label="loc_us-gaap_PreferredStockValue" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_PreferredStockValue" xml:lang="en-US">Preferred Stock, Value, Issued</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_PreferredStockValue" xml:lang="en-US">Preferred stock - $.001 par value; 10,000,000 shares authorized, 0 shares issued and outstanding at June 30, 2014 and December 31, 2013, respectively</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PreferredStockValue" xlink:to="lab_us-gaap_PreferredStockValue" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonStockValue" xlink:label="loc_us-gaap_CommonStockValue" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_CommonStockValue" xml:lang="en-US">Common Stock, Value, Issued</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_CommonStockValue" xml:lang="en-US">Common stock - $.001 par value; 75,000,000 shares authorized, 24,444,058 and 18,574,334 shares issued and outstanding at June 30, 2014 and December 31, 2013, respectively</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommonStockValue" xlink:to="lab_us-gaap_CommonStockValue" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="loc_us-gaap_AdditionalPaidInCapital" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_AdditionalPaidInCapital" xml:lang="en-US">Additional Paid in Capital, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_AdditionalPaidInCapital" xml:lang="en-US">Additional paid-in capital</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AdditionalPaidInCapital" xlink:to="lab_us-gaap_AdditionalPaidInCapital" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_RetainedEarningsAccumulatedDeficit" xml:lang="en-US">Retained Earnings (Accumulated Deficit), Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_RetainedEarningsAccumulatedDeficit" xml:lang="en-US">Accumulated deficit</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RetainedEarningsAccumulatedDeficit" xlink:to="lab_us-gaap_RetainedEarningsAccumulatedDeficit" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_StockholdersEquity" xml:lang="en-US">Stockholders Equity Attributable to Parent, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="lab_us-gaap_StockholdersEquity" xml:lang="en-US">Total stockholders&#39; equity</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="lab_us-gaap_StockholdersEquity" xml:lang="en-US">Balance</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="lab_us-gaap_StockholdersEquity" xml:lang="en-US">Balance</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockholdersEquity" xlink:to="lab_us-gaap_StockholdersEquity" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_LiabilitiesAndStockholdersEquity" xml:lang="en-US">Liabilities and Equity, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="lab_us-gaap_LiabilitiesAndStockholdersEquity" xml:lang="en-US">Total liabilities and stockholders&#39; equity</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="lab_us-gaap_LiabilitiesAndStockholdersEquity" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="loc_us-gaap_AccountingPoliciesAbstract" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_AccountingPoliciesAbstract" xml:lang="en-US">Accounting Policies [Abstract]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccountingPoliciesAbstract" xlink:to="lab_us-gaap_AccountingPoliciesAbstract" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xlink:label="loc_us-gaap_BasisOfAccountingPolicyPolicyTextBlock" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xml:lang="en-US">Basis Of Accounting, Policy [Policy Text Block]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xml:lang="en-US">Basis of Accounting, Policy [Policy Text Block]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xlink:to="lab_us-gaap_BasisOfAccountingPolicyPolicyTextBlock" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_UseOfEstimates" xlink:label="loc_us-gaap_UseOfEstimates" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_UseOfEstimates" xml:lang="en-US">Use Of Estimates, Policy [Policy Text Block]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_UseOfEstimates" xml:lang="en-US">Use of Estimates, Policy [Policy Text Block]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_UseOfEstimates" xlink:to="lab_us-gaap_UseOfEstimates" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:label="loc_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xml:lang="en-US">New Accounting Pronouncements, Policy [Policy Text Block]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xml:lang="en-US">New Accounting Pronouncements, Policy [Policy Text Block]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:to="lab_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DeferredCostsCapitalizedPrepaidAndOtherAssetsDisclosureTextBlock" xlink:label="loc_us-gaap_DeferredCostsCapitalizedPrepaidAndOtherAssetsDisclosureTextBlock" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_DeferredCostsCapitalizedPrepaidAndOtherAssetsDisclosureTextBlock" xml:lang="en-US">Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Table Text Block]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_DeferredCostsCapitalizedPrepaidAndOtherAssetsDisclosureTextBlock" xml:lang="en-US">Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Table Text Block]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DeferredCostsCapitalizedPrepaidAndOtherAssetsDisclosureTextBlock" xlink:to="lab_us-gaap_DeferredCostsCapitalizedPrepaidAndOtherAssetsDisclosureTextBlock" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTextBlock" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentTextBlock" xml:lang="en-US">Property, Plant and Equipment [Table Text Block]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentTextBlock" xml:lang="en-US">Property, Plant and Equipment [Table Text Block]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentTextBlock" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfIntangibleAssetsAndGoodwillTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfIntangibleAssetsAndGoodwillTableTextBlock" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ScheduleOfIntangibleAssetsAndGoodwillTableTextBlock" xml:lang="en-US">Schedule Of Intangible Assets and Goodwill [Table Text Block]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_ScheduleOfIntangibleAssetsAndGoodwillTableTextBlock" xml:lang="en-US">Schedule of Intangible Assets and Goodwill [Table Text Block]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfIntangibleAssetsAndGoodwillTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfIntangibleAssetsAndGoodwillTableTextBlock" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" xlink:label="loc_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" xml:lang="en-US">Schedule Of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" xml:lang="en-US">Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" xlink:to="lab_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfAccruedLiabilitiesTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfAccruedLiabilitiesTableTextBlock" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ScheduleOfAccruedLiabilitiesTableTextBlock" xml:lang="en-US">Schedule Of Accrued Liabilities [Table Text Block]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_ScheduleOfAccruedLiabilitiesTableTextBlock" xml:lang="en-US">Schedule of Accrued Liabilities [Table Text Block]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfAccruedLiabilitiesTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfAccruedLiabilitiesTableTextBlock" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EquityAbstract" xlink:label="loc_us-gaap_EquityAbstract" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_EquityAbstract" xml:lang="en-US">Equity [Abstract]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EquityAbstract" xlink:to="lab_us-gaap_EquityAbstract" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_SecuritiesPurchaseAgreementsAxis" xlink:label="loc_atos_SecuritiesPurchaseAgreementsAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_SecuritiesPurchaseAgreementsAxis" xml:lang="en-US">Securities Purchase Agreements [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_SecuritiesPurchaseAgreementsAxis" xlink:to="lab_atos_SecuritiesPurchaseAgreementsAxis" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_SecuritiesPurchaseAgreementsDomain" xlink:label="loc_atos_SecuritiesPurchaseAgreementsDomain" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_SecuritiesPurchaseAgreementsDomain" xml:lang="en-US">Securities Purchase Agreements [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_SecuritiesPurchaseAgreementsDomain" xlink:to="lab_atos_SecuritiesPurchaseAgreementsDomain" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_InvestorPlacementAgent1AndPlacementAgent2WarrantsMember" xlink:label="loc_atos_InvestorPlacementAgent1AndPlacementAgent2WarrantsMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_InvestorPlacementAgent1AndPlacementAgent2WarrantsMember" xml:lang="en-US">Investor, Placement Agent1 and Placement Agent2 Warrants [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_InvestorPlacementAgent1AndPlacementAgent2WarrantsMember" xlink:to="lab_atos_InvestorPlacementAgent1AndPlacementAgent2WarrantsMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_AcueityWarrantsMember" xlink:label="loc_atos_AcueityWarrantsMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_AcueityWarrantsMember" xml:lang="en-US">Acueity Warrants [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_AcueityWarrantsMember" xlink:to="lab_atos_AcueityWarrantsMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_Warrants2014AndPlacementAgentWarrantsMember" xlink:label="loc_atos_Warrants2014AndPlacementAgentWarrantsMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_Warrants2014AndPlacementAgentWarrantsMember" xml:lang="en-US">Warrants 2014 and Placement Agent Warrants [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_Warrants2014AndPlacementAgentWarrantsMember" xlink:to="lab_atos_Warrants2014AndPlacementAgentWarrantsMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_LeaseAgreementPeriodAxis" xlink:label="loc_atos_LeaseAgreementPeriodAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_LeaseAgreementPeriodAxis" xml:lang="en-US">Lease Agreement Period [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_LeaseAgreementPeriodAxis" xlink:to="lab_atos_LeaseAgreementPeriodAxis" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_LeaseAgreementPeriodDomain" xlink:label="loc_atos_LeaseAgreementPeriodDomain" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_LeaseAgreementPeriodDomain" xml:lang="en-US">Lease Agreement Period [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_LeaseAgreementPeriodDomain" xlink:to="lab_atos_LeaseAgreementPeriodDomain" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_LeaseAgreementDecember2011Member" xlink:label="loc_atos_LeaseAgreementDecember2011Member" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_LeaseAgreementDecember2011Member" xml:lang="en-US">Lease Agreement December 2011 [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_LeaseAgreementDecember2011Member" xlink:to="lab_atos_LeaseAgreementDecember2011Member" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_NameOfLessorAxis" xlink:label="loc_atos_NameOfLessorAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_NameOfLessorAxis" xml:lang="en-US">Name Of Lessor [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_NameOfLessorAxis" xlink:to="lab_atos_NameOfLessorAxis" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_NameOfLessorDomain" xlink:label="loc_atos_NameOfLessorDomain" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_NameOfLessorDomain" xml:lang="en-US">Name Of Lessor [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_NameOfLessorDomain" xlink:to="lab_atos_NameOfLessorDomain" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_AreLlcMember" xlink:label="loc_atos_AreLlcMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_AreLlcMember" xml:lang="en-US">ARE LLC [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_AreLlcMember" xlink:to="lab_atos_AreLlcMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock" xlink:label="loc_us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock" xml:lang="en-US">Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock" xml:lang="en-US">Schedule of Fair Value of Warrants [Table Text Block]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock" xlink:to="lab_us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingLeasesOfLesseeDisclosureTextBlock" xlink:label="loc_us-gaap_OperatingLeasesOfLesseeDisclosureTextBlock" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_OperatingLeasesOfLesseeDisclosureTextBlock" xml:lang="en-US">Operating Leases Of Lessee Disclosure [Table Text Block]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_OperatingLeasesOfLesseeDisclosureTextBlock" xml:lang="en-US">Operating Leases of Lessee Disclosure [Table Text Block]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeasesOfLesseeDisclosureTextBlock" xlink:to="lab_us-gaap_OperatingLeasesOfLesseeDisclosureTextBlock" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock" xml:lang="en-US">Schedule Of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock" xml:lang="en-US">Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xml:lang="en-US">Schedule Of Share-Based Compensation, Stock Options, Activity [Table Text Block]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xml:lang="en-US">Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:to="lab_us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PreferredStockParOrStatedValuePerShare" xlink:label="loc_us-gaap_PreferredStockParOrStatedValuePerShare" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_PreferredStockParOrStatedValuePerShare" xml:lang="en-US">Preferred Stock, Par or Stated Value Per Share</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_PreferredStockParOrStatedValuePerShare" xml:lang="en-US">Preferred stock, par value (in dollars per share)</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_PreferredStockParOrStatedValuePerShare" xml:lang="en-US">Preferred Stock, Par or Stated Value Per Share (in dollars per share)</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PreferredStockParOrStatedValuePerShare" xlink:to="lab_us-gaap_PreferredStockParOrStatedValuePerShare" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_PreferredStockSharesAuthorized" xml:lang="en-US">Preferred Stock, Shares Authorized</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_PreferredStockSharesAuthorized" xml:lang="en-US">Preferred stock, shares authorized</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PreferredStockSharesAuthorized" xlink:to="lab_us-gaap_PreferredStockSharesAuthorized" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PreferredStockSharesIssued" xlink:label="loc_us-gaap_PreferredStockSharesIssued" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_PreferredStockSharesIssued" xml:lang="en-US">Preferred Stock, Shares Issued</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_PreferredStockSharesIssued" xml:lang="en-US">Preferred stock, shares issued</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PreferredStockSharesIssued" xlink:to="lab_us-gaap_PreferredStockSharesIssued" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PreferredStockSharesOutstanding" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_PreferredStockSharesOutstanding" xml:lang="en-US">Preferred Stock, Shares Outstanding</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_PreferredStockSharesOutstanding" xml:lang="en-US">Preferred stock, shares outstanding</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PreferredStockSharesOutstanding" xlink:to="lab_us-gaap_PreferredStockSharesOutstanding" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_CommonStockParOrStatedValuePerShare" xml:lang="en-US">Common Stock, Par or Stated Value Per Share</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_CommonStockParOrStatedValuePerShare" xml:lang="en-US">Common stock, par value (in dollars per share)</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_CommonStockParOrStatedValuePerShare" xml:lang="en-US">Common Stock, Par or Stated Value Per Share (in dollars per share)</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommonStockParOrStatedValuePerShare" xlink:to="lab_us-gaap_CommonStockParOrStatedValuePerShare" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="loc_us-gaap_CommonStockSharesAuthorized" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_CommonStockSharesAuthorized" xml:lang="en-US">Common Stock, Shares Authorized</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_CommonStockSharesAuthorized" xml:lang="en-US">Common stock, authorized</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommonStockSharesAuthorized" xlink:to="lab_us-gaap_CommonStockSharesAuthorized" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonStockSharesIssued" xlink:label="loc_us-gaap_CommonStockSharesIssued" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_CommonStockSharesIssued" xml:lang="en-US">Common Stock, Shares, Issued</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_CommonStockSharesIssued" xml:lang="en-US">Common stock, shares issued</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommonStockSharesIssued" xlink:to="lab_us-gaap_CommonStockSharesIssued" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="loc_us-gaap_CommonStockSharesOutstanding" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_CommonStockSharesOutstanding" xml:lang="en-US">Common Stock, Shares, Outstanding</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_CommonStockSharesOutstanding" xml:lang="en-US">Common stock, shares outstanding</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommonStockSharesOutstanding" xlink:to="lab_us-gaap_CommonStockSharesOutstanding" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:label="loc_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xml:lang="en-US">Organization, Consolidation and Presentation of Financial Statements [Abstract]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:to="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_NatureOfOperationsTable" xlink:label="loc_atos_NatureOfOperationsTable" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_NatureOfOperationsTable" xml:lang="en-US">Nature Of Operations [Table]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_NatureOfOperationsTable" xlink:to="lab_atos_NatureOfOperationsTable" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_NatureOfOperationsLineItems" xlink:label="loc_atos_NatureOfOperationsLineItems" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_NatureOfOperationsLineItems" xml:lang="en-US">Nature Of Operations [Line Items]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_NatureOfOperationsLineItems" xlink:to="lab_atos_NatureOfOperationsLineItems" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CashAcquiredFromAcquisition" xlink:label="loc_us-gaap_CashAcquiredFromAcquisition" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_CashAcquiredFromAcquisition" xml:lang="en-US">Cash Acquired From Acquisition</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_CashAcquiredFromAcquisition" xml:lang="en-US">Cash Acquired from Acquisition</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CashAcquiredFromAcquisition" xlink:to="lab_us-gaap_CashAcquiredFromAcquisition" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_DeferredCostsCapitalizedPrepaidAndOtherAssetsTable" xlink:label="loc_atos_DeferredCostsCapitalizedPrepaidAndOtherAssetsTable" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_DeferredCostsCapitalizedPrepaidAndOtherAssetsTable" xml:lang="en-US">Deferred Costs, Capitalized, Prepaid, and Other Assets [Table]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_DeferredCostsCapitalizedPrepaidAndOtherAssetsTable" xlink:to="lab_atos_DeferredCostsCapitalizedPrepaidAndOtherAssetsTable" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_DeferredCostsCapitalizedPrepaidAndOtherAssetsLineItems" xlink:label="loc_atos_DeferredCostsCapitalizedPrepaidAndOtherAssetsLineItems" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_DeferredCostsCapitalizedPrepaidAndOtherAssetsLineItems" xml:lang="en-US">Deferred Costs, Capitalized, Prepaid, and Other Assets [Line Items]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_DeferredCostsCapitalizedPrepaidAndOtherAssetsLineItems" xlink:to="lab_atos_DeferredCostsCapitalizedPrepaidAndOtherAssetsLineItems" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PrepaidAdvertising" xlink:label="loc_us-gaap_PrepaidAdvertising" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_PrepaidAdvertising" xml:lang="en-US">Prepaid Advertising</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_PrepaidAdvertising" xml:lang="en-US">Tradeshow and other marketing events</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PrepaidAdvertising" xlink:to="lab_us-gaap_PrepaidAdvertising" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PrepaidInsurance" xlink:label="loc_us-gaap_PrepaidInsurance" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_PrepaidInsurance" xml:lang="en-US">Prepaid Insurance</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_PrepaidInsurance" xml:lang="en-US">Prepaid insurance</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PrepaidInsurance" xlink:to="lab_us-gaap_PrepaidInsurance" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_Supplies" xlink:label="loc_us-gaap_Supplies" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_Supplies" xml:lang="en-US">Prepaid Supplies</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_Supplies" xml:lang="en-US">Prepaid hardware and software</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_Supplies" xlink:to="lab_us-gaap_Supplies" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DepositAssets" xlink:label="loc_us-gaap_DepositAssets" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_DepositAssets" xml:lang="en-US">Deposit Assets, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_DepositAssets" xml:lang="en-US">Retainer and security deposits</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DepositAssets" xlink:to="lab_us-gaap_DepositAssets" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherPrepaidExpenseCurrent" xlink:label="loc_us-gaap_OtherPrepaidExpenseCurrent" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_OtherPrepaidExpenseCurrent" xml:lang="en-US">Other Prepaid Expense, Current</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_OtherPrepaidExpenseCurrent" xml:lang="en-US">Other</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherPrepaidExpenseCurrent" xlink:to="lab_us-gaap_OtherPrepaidExpenseCurrent" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xml:lang="en-US">Property, Plant and Equipment [Table]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:to="lab_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentLineItems" xml:lang="en-US">Property, Plant and Equipment [Line Items]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentLineItems" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MachineryAndEquipmentGross" xlink:label="loc_us-gaap_MachineryAndEquipmentGross" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_MachineryAndEquipmentGross" xml:lang="en-US">Machinery and Equipment, Gross</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_MachineryAndEquipmentGross" xml:lang="en-US">Machinery and equipment</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_MachineryAndEquipmentGross" xlink:to="lab_us-gaap_MachineryAndEquipmentGross" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LeaseholdImprovementsGross" xlink:label="loc_us-gaap_LeaseholdImprovementsGross" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_LeaseholdImprovementsGross" xml:lang="en-US">Leasehold Improvements, Gross</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_LeaseholdImprovementsGross" xml:lang="en-US">Leasehold improvements</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LeaseholdImprovementsGross" xlink:to="lab_us-gaap_LeaseholdImprovementsGross" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_CapitalizedNewProductDevelopmentCosts" xlink:label="loc_atos_CapitalizedNewProductDevelopmentCosts" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_CapitalizedNewProductDevelopmentCosts" xml:lang="en-US">Capitalized New Product Development Costs</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_CapitalizedNewProductDevelopmentCosts" xml:lang="en-US">Capitalized new product development costs</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_CapitalizedNewProductDevelopmentCosts" xml:lang="en-US">Capitalized costs incurred for development of new product for internal use.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_CapitalizedNewProductDevelopmentCosts" xlink:to="lab_atos_CapitalizedNewProductDevelopmentCosts" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xml:lang="en-US">Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="lab_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xml:lang="en-US">Less: Accumulated depreciation</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:to="lab_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_AllowanceForLossOnImpairmentOfAssets" xlink:label="loc_atos_AllowanceForLossOnImpairmentOfAssets" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_AllowanceForLossOnImpairmentOfAssets" xml:lang="en-US">Allowance For Loss on Impairment Of Assets</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="lab_atos_AllowanceForLossOnImpairmentOfAssets" xml:lang="en-US">Less: Allowance for loss on impairment</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_AllowanceForLossOnImpairmentOfAssets" xml:lang="en-US">The amount of allowance for loss on impairment of assets at the balance sheet date.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_AllowanceForLossOnImpairmentOfAssets" xlink:to="lab_atos_AllowanceForLossOnImpairmentOfAssets" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_Depreciation" xlink:label="loc_us-gaap_Depreciation" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_Depreciation" xml:lang="en-US">Depreciation, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_Depreciation" xml:lang="en-US">Depreciation</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_Depreciation" xlink:to="lab_us-gaap_Depreciation" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xml:lang="en-US">Schedule of Finite-Lived Intangible Assets [Table]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:to="lab_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsLineItems" xml:lang="en-US">Finite-Lived Intangible Assets [Line Items]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsLineItems" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedPatentsGross" xlink:label="loc_us-gaap_FiniteLivedPatentsGross" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_FiniteLivedPatentsGross" xml:lang="en-US">Finite-Lived Patents, Gross</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_FiniteLivedPatentsGross" xml:lang="en-US">Patents</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedPatentsGross" xlink:to="lab_us-gaap_FiniteLivedPatentsGross" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedLicenseAgreementsGross" xlink:label="loc_us-gaap_FiniteLivedLicenseAgreementsGross" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_FiniteLivedLicenseAgreementsGross" xml:lang="en-US">Finite-Lived License Agreements, Gross</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_FiniteLivedLicenseAgreementsGross" xml:lang="en-US">Capitalized license costs</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedLicenseAgreementsGross" xlink:to="lab_us-gaap_FiniteLivedLicenseAgreementsGross" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CapitalizedComputerSoftwareGross" xlink:label="loc_us-gaap_CapitalizedComputerSoftwareGross" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_CapitalizedComputerSoftwareGross" xml:lang="en-US">Capitalized Computer Software, Gross</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_CapitalizedComputerSoftwareGross" xml:lang="en-US">Software</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CapitalizedComputerSoftwareGross" xlink:to="lab_us-gaap_CapitalizedComputerSoftwareGross" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xml:lang="en-US">Finite-Lived Intangible Assets, Accumulated Amortization</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xml:lang="en-US">Less: Accumulated amortization</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xml:lang="en-US">Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xml:lang="en-US">2014 (includes the remainder of the year)</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xml:lang="en-US">Finite-Lived Intangible Assets, Amortization Expense, Year Two</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xml:lang="en-US">2015</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xml:lang="en-US">Finite-Lived Intangible Assets, Amortization Expense, Year Three</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xml:lang="en-US">2016</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xml:lang="en-US">Finite-Lived Intangible Assets, Amortization Expense, Year Four</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xml:lang="en-US">2017</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xml:lang="en-US">Finite-Lived Intangible Assets, Amortization Expense, Year Five</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xml:lang="en-US">2018</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" xml:lang="en-US">Finite-Lived Intangible Assets, Amortization Expense, after Year Five</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" xml:lang="en-US">Thereafter</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncomeStatementAbstract" xlink:label="loc_us-gaap_IncomeStatementAbstract" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_IncomeStatementAbstract" xml:lang="en-US">Income Statement [Abstract]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeStatementAbstract" xlink:to="lab_us-gaap_IncomeStatementAbstract" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RevenuesAbstract" xlink:label="loc_us-gaap_RevenuesAbstract" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_RevenuesAbstract" xml:lang="en-US">Revenues [Abstract]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_RevenuesAbstract" xml:lang="en-US">Revenue</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RevenuesAbstract" xlink:to="lab_us-gaap_RevenuesAbstract" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SalesRevenueServicesNet" xlink:label="loc_us-gaap_SalesRevenueServicesNet" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SalesRevenueServicesNet" xml:lang="en-US">Sales Revenue, Services, Net</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_SalesRevenueServicesNet" xml:lang="en-US">Diagnostic testing service</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SalesRevenueServicesNet" xlink:to="lab_us-gaap_SalesRevenueServicesNet" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SalesRevenueGoodsNet" xlink:label="loc_us-gaap_SalesRevenueGoodsNet" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SalesRevenueGoodsNet" xml:lang="en-US">Sales Revenue, Goods, Net</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_SalesRevenueGoodsNet" xml:lang="en-US">Product sales</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SalesRevenueGoodsNet" xlink:to="lab_us-gaap_SalesRevenueGoodsNet" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SalesRevenueNet" xlink:label="loc_us-gaap_SalesRevenueNet" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SalesRevenueNet" xml:lang="en-US">Revenue, Net, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_SalesRevenueNet" xml:lang="en-US">Revenue, Net</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="lab_us-gaap_SalesRevenueNet" xml:lang="en-US">Total Revenue</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SalesRevenueNet" xlink:to="lab_us-gaap_SalesRevenueNet" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CostOfRevenueAbstract" xlink:label="loc_us-gaap_CostOfRevenueAbstract" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_CostOfRevenueAbstract" xml:lang="en-US">Cost Of Revenue [Abstract]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_CostOfRevenueAbstract" xml:lang="en-US">Cost of Revenue</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CostOfRevenueAbstract" xlink:to="lab_us-gaap_CostOfRevenueAbstract" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CostOfServices" xlink:label="loc_us-gaap_CostOfServices" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_CostOfServices" xml:lang="en-US">Cost of Services, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_CostOfServices" xml:lang="en-US">Diagnostic testing service</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_CostOfServices" xml:lang="en-US">Cost of Services</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CostOfServices" xlink:to="lab_us-gaap_CostOfServices" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CostOfGoodsSold" xlink:label="loc_us-gaap_CostOfGoodsSold" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_CostOfGoodsSold" xml:lang="en-US">Cost of Goods Sold, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_CostOfGoodsSold" xml:lang="en-US">Product sales</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CostOfGoodsSold" xlink:to="lab_us-gaap_CostOfGoodsSold" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CostOfRevenue" xlink:label="loc_us-gaap_CostOfRevenue" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_CostOfRevenue" xml:lang="en-US">Cost of Revenue, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="lab_us-gaap_CostOfRevenue" xml:lang="en-US">Total Cost of Revenue</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CostOfRevenue" xlink:to="lab_us-gaap_CostOfRevenue" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_GrossProfit" xlink:label="loc_us-gaap_GrossProfit" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_GrossProfit" xml:lang="en-US">Gross Profit, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="lab_us-gaap_GrossProfit" xml:lang="en-US">Gross Profit</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_GrossProfit" xlink:to="lab_us-gaap_GrossProfit" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SellingExpense" xlink:label="loc_us-gaap_SellingExpense" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SellingExpense" xml:lang="en-US">Selling Expense</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_SellingExpense" xml:lang="en-US">Selling expenses</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SellingExpense" xlink:to="lab_us-gaap_SellingExpense" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ResearchAndDevelopmentExpense" xml:lang="en-US">Research and Development Expense, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_ResearchAndDevelopmentExpense" xml:lang="en-US">Research and development expenses</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ResearchAndDevelopmentExpense" xlink:to="lab_us-gaap_ResearchAndDevelopmentExpense" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_GeneralAndAdministrativeExpense" xml:lang="en-US">General and Administrative Expense, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_GeneralAndAdministrativeExpense" xml:lang="en-US">General and administrative expenses</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_GeneralAndAdministrativeExpense" xlink:to="lab_us-gaap_GeneralAndAdministrativeExpense" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingExpenses" xlink:label="loc_us-gaap_OperatingExpenses" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_OperatingExpenses" xml:lang="en-US">Operating Expenses, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="lab_us-gaap_OperatingExpenses" xml:lang="en-US">Total operating expenses</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingExpenses" xlink:to="lab_us-gaap_OperatingExpenses" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="loc_us-gaap_OperatingIncomeLoss" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_OperatingIncomeLoss" xml:lang="en-US">Operating Income (Loss), Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="lab_us-gaap_OperatingIncomeLoss" xml:lang="en-US">Operating Loss</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingIncomeLoss" xlink:to="lab_us-gaap_OperatingIncomeLoss" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_InvestmentIncomeInterest" xlink:label="loc_us-gaap_InvestmentIncomeInterest" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_InvestmentIncomeInterest" xml:lang="en-US">Investment Income, Interest</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_InvestmentIncomeInterest" xml:lang="en-US">Interest income</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InvestmentIncomeInterest" xlink:to="lab_us-gaap_InvestmentIncomeInterest" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_InterestExpense" xlink:label="loc_us-gaap_InterestExpense" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_InterestExpense" xml:lang="en-US">Interest Expense, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_InterestExpense" xml:lang="en-US">Interest expense</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InterestExpense" xlink:to="lab_us-gaap_InterestExpense" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xml:lang="en-US">Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="lab_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xml:lang="en-US">Loss before Income Taxes</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:to="lab_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_IncomeTaxExpenseBenefit" xml:lang="en-US">Income Tax Expense (Benefit)</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_IncomeTaxExpenseBenefit" xml:lang="en-US">Income Taxes</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefit" xlink:to="lab_us-gaap_IncomeTaxExpenseBenefit" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_NetIncomeLoss" xml:lang="en-US">Net Income (Loss) Attributable to Parent, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="lab_us-gaap_NetIncomeLoss" xml:lang="en-US">Net Loss</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/disclosureGuidance" xlink:label="lab_us-gaap_NetIncomeLoss" xml:lang="en-US">Net loss for the six months ended June 30, 2014</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetIncomeLoss" xlink:to="lab_us-gaap_NetIncomeLoss" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EarningsPerShareBasicAndDiluted" xlink:label="loc_us-gaap_EarningsPerShareBasicAndDiluted" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_EarningsPerShareBasicAndDiluted" xml:lang="en-US">Earnings Per Share, Basic and Diluted, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_EarningsPerShareBasicAndDiluted" xml:lang="en-US">Loss per common share - basic and diluted (in dollars per share)</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EarningsPerShareBasicAndDiluted" xlink:to="lab_us-gaap_EarningsPerShareBasicAndDiluted" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xlink:label="loc_us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xml:lang="en-US">Weighted Average Number Of Shares Outstanding, Basic and Diluted</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xml:lang="en-US">Weighted average shares outstanding, basic &amp; diluted (in shares)</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xlink:to="lab_us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xml:lang="en-US">Finite-Lived Intangible Assets by Major Class [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xml:lang="en-US">Finite-Lived Intangible Assets, Major Class Name [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ComputerSoftwareIntangibleAssetMember" xlink:label="loc_us-gaap_ComputerSoftwareIntangibleAssetMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ComputerSoftwareIntangibleAssetMember" xml:lang="en-US">Computer Software, Intangible Asset [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ComputerSoftwareIntangibleAssetMember" xlink:to="lab_us-gaap_ComputerSoftwareIntangibleAssetMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PatentsMember" xlink:label="loc_us-gaap_PatentsMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_PatentsMember" xml:lang="en-US">Patents [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PatentsMember" xlink:to="lab_us-gaap_PatentsMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_LaboratorySoftwareMember" xlink:label="loc_atos_LaboratorySoftwareMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_LaboratorySoftwareMember" xml:lang="en-US">Laboratory software [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_LaboratorySoftwareMember" xlink:to="lab_atos_LaboratorySoftwareMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_NewlyDevelopedWebsiteMember" xlink:label="loc_atos_NewlyDevelopedWebsiteMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_NewlyDevelopedWebsiteMember" xml:lang="en-US">Newly developed website [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_NewlyDevelopedWebsiteMember" xlink:to="lab_atos_NewlyDevelopedWebsiteMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_CompanyWebsiteMember" xlink:label="loc_atos_CompanyWebsiteMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_CompanyWebsiteMember" xml:lang="en-US">Company Website [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_CompanyWebsiteMember" xlink:to="lab_atos_CompanyWebsiteMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SoftwareLicenseArrangementMember" xlink:label="loc_us-gaap_SoftwareLicenseArrangementMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SoftwareLicenseArrangementMember" xml:lang="en-US">Software License Arrangement [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_SoftwareLicenseArrangementMember" xml:lang="en-US">Capitalized license costs [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SoftwareLicenseArrangementMember" xlink:to="lab_us-gaap_SoftwareLicenseArrangementMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_RangeAxis" xml:lang="en-US">Range [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RangeAxis" xlink:to="lab_us-gaap_RangeAxis" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_RangeMember" xml:lang="en-US">Range [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RangeMember" xlink:to="lab_us-gaap_RangeMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_MinimumMember" xml:lang="en-US">Minimum [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_MinimumMember" xlink:to="lab_us-gaap_MinimumMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_MaximumMember" xml:lang="en-US">Maximum [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_MaximumMember" xlink:to="lab_us-gaap_MaximumMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_AmortizationOfIntangibleAssets" xml:lang="en-US">Amortization Of Intangible Assets</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_AmortizationOfIntangibleAssets" xml:lang="en-US">Amortization of Intangible Assets</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AmortizationOfIntangibleAssets" xlink:to="lab_us-gaap_AmortizationOfIntangibleAssets" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FinitelivedIntangibleAssetsAcquired1" xlink:label="loc_us-gaap_FinitelivedIntangibleAssetsAcquired1" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_FinitelivedIntangibleAssetsAcquired1" xml:lang="en-US">Finite-lived Intangible Assets Acquired</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FinitelivedIntangibleAssetsAcquired1" xlink:to="lab_us-gaap_FinitelivedIntangibleAssetsAcquired1" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetUsefulLife" xml:lang="en-US">Finite-Lived Intangible Asset, Useful Life</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetUsefulLife" xml:lang="en-US">Finite-Lived Intangible Asset, Useful Life (in years)</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetUsefulLife" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_PayrollLiabilitiesTable" xlink:label="loc_atos_PayrollLiabilitiesTable" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_PayrollLiabilitiesTable" xml:lang="en-US">Payroll Liabilities [Table]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_PayrollLiabilitiesTable" xlink:to="lab_atos_PayrollLiabilitiesTable" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_PayrollLiabilitiesLineItems" xlink:label="loc_atos_PayrollLiabilitiesLineItems" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_PayrollLiabilitiesLineItems" xml:lang="en-US">Payroll Liabilities [Line Items]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_PayrollLiabilitiesLineItems" xlink:to="lab_atos_PayrollLiabilitiesLineItems" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccruedBonusesCurrent" xlink:label="loc_us-gaap_AccruedBonusesCurrent" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_AccruedBonusesCurrent" xml:lang="en-US">Accrued Bonuses, Current</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_AccruedBonusesCurrent" xml:lang="en-US">Accrued bonus payable</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccruedBonusesCurrent" xlink:to="lab_us-gaap_AccruedBonusesCurrent" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccruedSalariesCurrent" xlink:label="loc_us-gaap_AccruedSalariesCurrent" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_AccruedSalariesCurrent" xml:lang="en-US">Accrued Salaries, Current</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_AccruedSalariesCurrent" xml:lang="en-US">Accrued payroll liabilities</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccruedSalariesCurrent" xlink:to="lab_us-gaap_AccruedSalariesCurrent" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccruedPayrollTaxesCurrent" xlink:label="loc_us-gaap_AccruedPayrollTaxesCurrent" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_AccruedPayrollTaxesCurrent" xml:lang="en-US">Accrued Payroll Taxes, Current</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_AccruedPayrollTaxesCurrent" xml:lang="en-US">Accrued payroll tax liabilities</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccruedPayrollTaxesCurrent" xlink:to="lab_us-gaap_AccruedPayrollTaxesCurrent" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_ShareBasedPaymentAwardStockWarrantsValuationAssumptionsTable" xlink:label="loc_atos_ShareBasedPaymentAwardStockWarrantsValuationAssumptionsTable" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_ShareBasedPaymentAwardStockWarrantsValuationAssumptionsTable" xml:lang="en-US">Share Based Payment Award Stock Warrants Valuation Assumptions [Table]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_ShareBasedPaymentAwardStockWarrantsValuationAssumptionsTable" xlink:to="lab_atos_ShareBasedPaymentAwardStockWarrantsValuationAssumptionsTable" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_StatementEquityComponentsAxis" xml:lang="en-US">Equity Components [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementEquityComponentsAxis" xlink:to="lab_us-gaap_StatementEquityComponentsAxis" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_EquityComponentDomain" xml:lang="en-US">Equity Component [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EquityComponentDomain" xlink:to="lab_us-gaap_EquityComponentDomain" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_InvestorWarrants2014Member" xlink:label="loc_atos_InvestorWarrants2014Member" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_InvestorWarrants2014Member" xml:lang="en-US">Investor Warrants 2014 [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_InvestorWarrants2014Member" xlink:to="lab_atos_InvestorWarrants2014Member" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_PlacementAgentWarrantsMember" xlink:label="loc_atos_PlacementAgentWarrantsMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_PlacementAgentWarrantsMember" xml:lang="en-US">Placement Agent Warrants [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_PlacementAgentWarrantsMember" xlink:to="lab_atos_PlacementAgentWarrantsMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_FairValueByFairValueHierarchyLevelAxis" xml:lang="en-US">Fair Value, Hierarchy [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="lab_us-gaap_FairValueByFairValueHierarchyLevelAxis" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xml:lang="en-US">Fair Value Hierarchy [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="lab_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="loc_us-gaap_FairValueInputsLevel3Member" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_FairValueInputsLevel3Member" xml:lang="en-US">Fair Value, Inputs, Level 3 [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueInputsLevel3Member" xlink:to="lab_us-gaap_FairValueInputsLevel3Member" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="loc_us-gaap_FairValueInputsLevel2Member" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_FairValueInputsLevel2Member" xml:lang="en-US">Fair Value, Inputs, Level 2 [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueInputsLevel2Member" xlink:to="lab_us-gaap_FairValueInputsLevel2Member" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="loc_us-gaap_FairValueInputsLevel1Member" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_FairValueInputsLevel1Member" xml:lang="en-US">Fair Value, Inputs, Level 1 [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueInputsLevel1Member" xlink:to="lab_us-gaap_FairValueInputsLevel1Member" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_ShareBasedPaymentAwardStockWarrantsValuationAssumptionsLineItems" xlink:label="loc_atos_ShareBasedPaymentAwardStockWarrantsValuationAssumptionsLineItems" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_ShareBasedPaymentAwardStockWarrantsValuationAssumptionsLineItems" xml:lang="en-US">Share Based Payment Award Stock Warrants Valuation Assumptions [Line Items]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_ShareBasedPaymentAwardStockWarrantsValuationAssumptionsLineItems" xlink:to="lab_atos_ShareBasedPaymentAwardStockWarrantsValuationAssumptionsLineItems" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OptionIndexedToIssuersEquityIndexedShares" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityIndexedShares" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_OptionIndexedToIssuersEquityIndexedShares" xml:lang="en-US">Option Indexed To Issuer&#39;s Equity, Indexed Shares</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_OptionIndexedToIssuersEquityIndexedShares" xml:lang="en-US">Indexed shares</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_OptionIndexedToIssuersEquityIndexedShares" xml:lang="en-US">Indexed shares</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OptionIndexedToIssuersEquityIndexedShares" xlink:to="lab_us-gaap_OptionIndexedToIssuersEquityIndexedShares" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice" xml:lang="en-US">Share-Based Compensation Arrangement By Share-Based Payment Award, Fair Value Assumptions, Exercise Price</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice" xml:lang="en-US">Exercise price</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice" xml:lang="en-US">Exercise price of the options</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xml:lang="en-US">Share-Based Compensation Arrangement By Share-Based Payment Award, Fair Value Assumptions and Methodology [Abstract]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xml:lang="en-US">Significant assumptions:</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SharePrice" xlink:label="loc_us-gaap_SharePrice" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SharePrice" xml:lang="en-US">Share Price</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_SharePrice" xml:lang="en-US">Stock price</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SharePrice" xlink:to="lab_us-gaap_SharePrice" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xml:lang="en-US">Share-Based Compensation Arrangement By Share-Based Payment Award, Fair Value Assumptions, Expected Term</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xml:lang="en-US">Remaining term</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xml:lang="en-US">Expected life of the options (years)</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:to="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMinimum" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMinimum" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMinimum" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMinimum" xml:lang="en-US">Risk free rate</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMinimum" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMinimum" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xml:lang="en-US">Share-Based Compensation Arrangement By Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xml:lang="en-US">Expected volatility</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xml:lang="en-US">Expected volatility</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_StockholdersEquityTable" xlink:label="loc_atos_StockholdersEquityTable" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_StockholdersEquityTable" xml:lang="en-US">Stockholders Equity [Table]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_StockholdersEquityTable" xlink:to="lab_atos_StockholdersEquityTable" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xml:lang="en-US">Related Party [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:to="lab_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaap_RelatedPartyDomain" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_RelatedPartyDomain" xml:lang="en-US">Related Party [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RelatedPartyDomain" xlink:to="lab_us-gaap_RelatedPartyDomain" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_EnsisheimPartnersLlcMember" xlink:label="loc_atos_EnsisheimPartnersLlcMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_EnsisheimPartnersLlcMember" xml:lang="en-US">Ensisheim Partners Llc [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_EnsisheimPartnersLlcMember" xlink:to="lab_atos_EnsisheimPartnersLlcMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_ManisteeVenturesLlcMember" xlink:label="loc_atos_ManisteeVenturesLlcMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_ManisteeVenturesLlcMember" xml:lang="en-US">Manistee Ventures Llc [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_ManisteeVenturesLlcMember" xlink:to="lab_atos_ManisteeVenturesLlcMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_FortyFourInvestorsMember" xlink:label="loc_atos_FortyFourInvestorsMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_FortyFourInvestorsMember" xml:lang="en-US">Forty Four Investors [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_FortyFourInvestorsMember" xml:lang="en-US">Investors (44) [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_FortyFourInvestorsMember" xlink:to="lab_atos_FortyFourInvestorsMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_ServicerMember" xlink:label="loc_atos_ServicerMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_ServicerMember" xml:lang="en-US">Servicer [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_ServicerMember" xlink:to="lab_atos_ServicerMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_ShareholderMember" xlink:label="loc_atos_ShareholderMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_ShareholderMember" xml:lang="en-US">Shareholder [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_ShareholderMember" xlink:to="lab_atos_ShareholderMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_InvestorMember" xlink:label="loc_us-gaap_InvestorMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_InvestorMember" xml:lang="en-US">Investor [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InvestorMember" xlink:to="lab_us-gaap_InvestorMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_WebsiteDevelopmentServicesMember" xlink:label="loc_atos_WebsiteDevelopmentServicesMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_WebsiteDevelopmentServicesMember" xml:lang="en-US">Website Development Services [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_WebsiteDevelopmentServicesMember" xlink:to="lab_atos_WebsiteDevelopmentServicesMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_ShareholdersOfAcueityMember" xlink:label="loc_atos_ShareholdersOfAcueityMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_ShareholdersOfAcueityMember" xml:lang="en-US">Shareholders Of Acueity [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_ShareholdersOfAcueityMember" xml:lang="en-US">Shareholders of Acueity [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_ShareholdersOfAcueityMember" xlink:to="lab_atos_ShareholdersOfAcueityMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_DrTimHunkapillerMember" xlink:label="loc_atos_DrTimHunkapillerMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_DrTimHunkapillerMember" xml:lang="en-US">Dr Tim Hunkapiller [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_DrTimHunkapillerMember" xml:lang="en-US">Dr. Tim Hunkapiller [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_DrTimHunkapillerMember" xlink:to="lab_atos_DrTimHunkapillerMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_EmployeesAndOfficersMember" xlink:label="loc_atos_EmployeesAndOfficersMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_EmployeesAndOfficersMember" xml:lang="en-US">Employees and Officers [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_EmployeesAndOfficersMember" xlink:to="lab_atos_EmployeesAndOfficersMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_NonEmployeeDirectorsMember" xlink:label="loc_atos_NonEmployeeDirectorsMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_NonEmployeeDirectorsMember" xml:lang="en-US">Non Employee Directors [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_NonEmployeeDirectorsMember" xml:lang="en-US">Non-Employee Directors [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_NonEmployeeDirectorsMember" xlink:to="lab_atos_NonEmployeeDirectorsMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_AspireCapitalFundLlcMember" xlink:label="loc_atos_AspireCapitalFundLlcMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_AspireCapitalFundLlcMember" xml:lang="en-US">Aspire Capital Fund, Llc [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_AspireCapitalFundLlcMember" xlink:to="lab_atos_AspireCapitalFundLlcMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_VendorsMember" xlink:label="loc_atos_VendorsMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_VendorsMember" xml:lang="en-US">Vendors [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_VendorsMember" xlink:to="lab_atos_VendorsMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_TitleOfIndividualAxis" xlink:label="loc_us-gaap_TitleOfIndividualAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_TitleOfIndividualAxis" xml:lang="en-US">Title of Individual [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_TitleOfIndividualAxis" xlink:to="lab_us-gaap_TitleOfIndividualAxis" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain" xml:lang="en-US">Relationship to Entity [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain" xlink:to="lab_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ChiefExecutiveOfficerMember" xlink:label="loc_us-gaap_ChiefExecutiveOfficerMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ChiefExecutiveOfficerMember" xml:lang="en-US">Chief Executive Officer [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_ChiefExecutiveOfficerMember" xml:lang="en-US">Chief Executive Officer [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ChiefExecutiveOfficerMember" xlink:to="lab_us-gaap_ChiefExecutiveOfficerMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DirectorMember" xlink:label="loc_us-gaap_DirectorMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_DirectorMember" xml:lang="en-US">Director [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_DirectorMember" xml:lang="en-US">Director [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DirectorMember" xlink:to="lab_us-gaap_DirectorMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_MemberOfBoardOfDirectorsMember" xlink:label="loc_atos_MemberOfBoardOfDirectorsMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_MemberOfBoardOfDirectorsMember" xml:lang="en-US">Member Of Board Of Directors [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_MemberOfBoardOfDirectorsMember" xml:lang="en-US">Member of Board of Directors [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_MemberOfBoardOfDirectorsMember" xlink:to="lab_atos_MemberOfBoardOfDirectorsMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_VariousEmployeesMember" xlink:label="loc_atos_VariousEmployeesMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_VariousEmployeesMember" xml:lang="en-US">Various Employees [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_VariousEmployeesMember" xml:lang="en-US">Various Employees [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_VariousEmployeesMember" xlink:to="lab_atos_VariousEmployeesMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_PlacementAgentMember" xlink:label="loc_atos_PlacementAgentMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_PlacementAgentMember" xml:lang="en-US">Placement Agent [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_PlacementAgentMember" xlink:to="lab_atos_PlacementAgentMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_StockSplitAxis" xlink:label="loc_atos_StockSplitAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_StockSplitAxis" xml:lang="en-US">Stock Split [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_StockSplitAxis" xlink:to="lab_atos_StockSplitAxis" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_StockSplitDomain" xlink:label="loc_atos_StockSplitDomain" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_StockSplitDomain" xml:lang="en-US">Stock Split [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_StockSplitDomain" xlink:to="lab_atos_StockSplitDomain" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_PriorToReverseShareSplitMember" xlink:label="loc_atos_PriorToReverseShareSplitMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_PriorToReverseShareSplitMember" xml:lang="en-US">Prior To Reverse Share Split [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_PriorToReverseShareSplitMember" xml:lang="en-US">Prior to Reverse Share Split on September 28, 2010 [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_PriorToReverseShareSplitMember" xlink:to="lab_atos_PriorToReverseShareSplitMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="loc_us-gaap_SubsequentEventTypeAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SubsequentEventTypeAxis" xml:lang="en-US">Subsequent Event Type [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubsequentEventTypeAxis" xlink:to="lab_us-gaap_SubsequentEventTypeAxis" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SubsequentEventTypeDomain" xml:lang="en-US">Subsequent Event Type [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubsequentEventTypeDomain" xlink:to="lab_us-gaap_SubsequentEventTypeDomain" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_SecuritiesPurchaseAgreementsInvestorMember" xlink:label="loc_atos_SecuritiesPurchaseAgreementsInvestorMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_SecuritiesPurchaseAgreementsInvestorMember" xml:lang="en-US">Securities Purchase Agreements, Investor [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_SecuritiesPurchaseAgreementsInvestorMember" xlink:to="lab_atos_SecuritiesPurchaseAgreementsInvestorMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_SecuritiesPurchaseAgreementsInvestorWarrantsMember" xlink:label="loc_atos_SecuritiesPurchaseAgreementsInvestorWarrantsMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_SecuritiesPurchaseAgreementsInvestorWarrantsMember" xml:lang="en-US">Securities Purchase Agreements, Investor Warrants [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_SecuritiesPurchaseAgreementsInvestorWarrantsMember" xlink:to="lab_atos_SecuritiesPurchaseAgreementsInvestorWarrantsMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_PlacementAgentAdditionalWarrantsMember" xlink:label="loc_atos_PlacementAgentAdditionalWarrantsMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_PlacementAgentAdditionalWarrantsMember" xml:lang="en-US">Placement Agent Additional Warrants [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_PlacementAgentAdditionalWarrantsMember" xlink:to="lab_atos_PlacementAgentAdditionalWarrantsMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_PlacementAgent1Member" xlink:label="loc_atos_PlacementAgent1Member" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_PlacementAgent1Member" xml:lang="en-US">Placement Agent1 [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_PlacementAgent1Member" xlink:to="lab_atos_PlacementAgent1Member" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_PlacementAgent2Member" xlink:label="loc_atos_PlacementAgent2Member" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_PlacementAgent2Member" xml:lang="en-US">Placement Agent2 [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_PlacementAgent2Member" xlink:to="lab_atos_PlacementAgent2Member" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_PrivatePlacementToAccreditedInvestorsMember" xlink:label="loc_atos_PrivatePlacementToAccreditedInvestorsMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_PrivatePlacementToAccreditedInvestorsMember" xml:lang="en-US">Private Placement To Accredited Investors [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_PrivatePlacementToAccreditedInvestorsMember" xml:lang="en-US">Private Placement to Accredited Investors [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_PrivatePlacementToAccreditedInvestorsMember" xlink:to="lab_atos_PrivatePlacementToAccreditedInvestorsMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SubsidiarySaleOfStockAxis" xml:lang="en-US">Subsidiary, Sale of Stock [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis" xlink:to="lab_us-gaap_SubsidiarySaleOfStockAxis" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SaleOfStockNameOfTransactionDomain" xml:lang="en-US">Sale of Stock, Name of Transaction [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain" xlink:to="lab_us-gaap_SaleOfStockNameOfTransactionDomain" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PrivatePlacementMember" xlink:label="loc_us-gaap_PrivatePlacementMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_PrivatePlacementMember" xml:lang="en-US">Private Placement [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PrivatePlacementMember" xlink:to="lab_us-gaap_PrivatePlacementMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IPOMember" xlink:label="loc_us-gaap_IPOMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_IPOMember" xml:lang="en-US">Ipo [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_IPOMember" xml:lang="en-US">IPO [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IPOMember" xlink:to="lab_us-gaap_IPOMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_InvestorWarrantsMember" xlink:label="loc_atos_InvestorWarrantsMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_InvestorWarrantsMember" xml:lang="en-US">Investor Warrants [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_InvestorWarrantsMember" xlink:to="lab_atos_InvestorWarrantsMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_WarrantMember" xlink:label="loc_us-gaap_WarrantMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_WarrantMember" xml:lang="en-US">Warrant [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_WarrantMember" xlink:to="lab_us-gaap_WarrantMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="loc_us-gaap_PlanNameAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_PlanNameAxis" xml:lang="en-US">Plan Name [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PlanNameAxis" xlink:to="lab_us-gaap_PlanNameAxis" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_PlanNameDomain" xml:lang="en-US">Plan Name [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PlanNameDomain" xlink:to="lab_us-gaap_PlanNameDomain" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_StockOptionAndIncentivePlan2010Member" xlink:label="loc_atos_StockOptionAndIncentivePlan2010Member" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_StockOptionAndIncentivePlan2010Member" xml:lang="en-US">Stock Option and Incentive Plan 2010 [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_StockOptionAndIncentivePlan2010Member" xlink:to="lab_atos_StockOptionAndIncentivePlan2010Member" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_TwoThousandAndFourteenPublicOfferingMember" xlink:label="loc_atos_TwoThousandAndFourteenPublicOfferingMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_TwoThousandAndFourteenPublicOfferingMember" xml:lang="en-US">Two Thousand and Fourteen Public Offering [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_TwoThousandAndFourteenPublicOfferingMember" xml:lang="en-US">2014 Public Offering [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_TwoThousandAndFourteenPublicOfferingMember" xlink:to="lab_atos_TwoThousandAndFourteenPublicOfferingMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_TwoThousandAndElevenPrivatePlacementMember" xlink:label="loc_atos_TwoThousandAndElevenPrivatePlacementMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_TwoThousandAndElevenPrivatePlacementMember" xml:lang="en-US">Two Thousand And Eleven Private Placement [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_TwoThousandAndElevenPrivatePlacementMember" xml:lang="en-US">2011 Private Placement [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_TwoThousandAndElevenPrivatePlacementMember" xlink:to="lab_atos_TwoThousandAndElevenPrivatePlacementMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_TwoThousandAndThirteenPublicOfferingMember" xlink:label="loc_atos_TwoThousandAndThirteenPublicOfferingMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_TwoThousandAndThirteenPublicOfferingMember" xml:lang="en-US">Two Thousand and Thirteen Public Offering [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_TwoThousandAndThirteenPublicOfferingMember" xml:lang="en-US">2013 Public Offering [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_TwoThousandAndThirteenPublicOfferingMember" xlink:to="lab_atos_TwoThousandAndThirteenPublicOfferingMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_AcuietyWarrantsMember" xlink:label="loc_atos_AcuietyWarrantsMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_AcuietyWarrantsMember" xml:lang="en-US">Acuiety Warrants [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_AcuietyWarrantsMember" xlink:to="lab_atos_AcuietyWarrantsMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_OutsideConsultingFirmMember" xlink:label="loc_atos_OutsideConsultingFirmMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_OutsideConsultingFirmMember" xml:lang="en-US">outside consulting firm [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_OutsideConsultingFirmMember" xlink:to="lab_atos_OutsideConsultingFirmMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" xml:lang="en-US">Major Types of Debt and Equity Securities [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" xlink:to="lab_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xml:lang="en-US">Major Types of Debt and Equity Securities [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:to="lab_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_NonQualifiedUnder2010StockOptionPlanMember" xlink:label="loc_atos_NonQualifiedUnder2010StockOptionPlanMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_NonQualifiedUnder2010StockOptionPlanMember" xml:lang="en-US">Non Qualified Under 2010 Stock Option Plan [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_NonQualifiedUnder2010StockOptionPlanMember" xml:lang="en-US">Non-Qualified Under 2010 Stock Option Plan [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_NonQualifiedUnder2010StockOptionPlanMember" xlink:to="lab_atos_NonQualifiedUnder2010StockOptionPlanMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_IncentiveStockOptionsUnder2010PlanMember" xlink:label="loc_atos_IncentiveStockOptionsUnder2010PlanMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_IncentiveStockOptionsUnder2010PlanMember" xml:lang="en-US">Incentive Stock Options Under 2010 Plan [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_IncentiveStockOptionsUnder2010PlanMember" xlink:to="lab_atos_IncentiveStockOptionsUnder2010PlanMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_StockOptionsUnder2010PlanMember" xlink:label="loc_atos_StockOptionsUnder2010PlanMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_StockOptionsUnder2010PlanMember" xml:lang="en-US">Stock Options Under 2010 Plan [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_StockOptionsUnder2010PlanMember" xlink:to="lab_atos_StockOptionsUnder2010PlanMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_InducementStockOptions2010PlansMember" xlink:label="loc_atos_InducementStockOptions2010PlansMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_InducementStockOptions2010PlansMember" xml:lang="en-US">Inducement Stock Options 2010 Plans [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_InducementStockOptions2010PlansMember" xlink:to="lab_atos_InducementStockOptions2010PlansMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_EmployeesUnder2010StockOptionPlanMember" xlink:label="loc_atos_EmployeesUnder2010StockOptionPlanMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_EmployeesUnder2010StockOptionPlanMember" xml:lang="en-US">Employees Under 2010 Stock Option Plan [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_EmployeesUnder2010StockOptionPlanMember" xlink:to="lab_atos_EmployeesUnder2010StockOptionPlanMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_AwardTypeAxis" xml:lang="en-US">Award Type [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AwardTypeAxis" xlink:to="lab_us-gaap_AwardTypeAxis" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xml:lang="en-US">Equity Award [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RestrictedStockMember" xlink:label="loc_us-gaap_RestrictedStockMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_RestrictedStockMember" xml:lang="en-US">Restricted Stock [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RestrictedStockMember" xlink:to="lab_us-gaap_RestrictedStockMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_StatementClassOfStockAxis" xml:lang="en-US">Class of Stock [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementClassOfStockAxis" xlink:to="lab_us-gaap_StatementClassOfStockAxis" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_TotalSharesAuthorized" xlink:label="loc_atos_TotalSharesAuthorized" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_TotalSharesAuthorized" xml:lang="en-US">Total Shares Authorized</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_TotalSharesAuthorized" xml:lang="en-US">Total Shares Authorized</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_TotalSharesAuthorized" xml:lang="en-US">The maximum number of shares permitted to be issued by an entity&#39;s charter and bylaws.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_TotalSharesAuthorized" xlink:to="lab_atos_TotalSharesAuthorized" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_CashFeeEqualsToPercentageOfGrossProceedsFromSaleOfCommonStockAndWarrants" xlink:label="loc_atos_CashFeeEqualsToPercentageOfGrossProceedsFromSaleOfCommonStockAndWarrants" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_CashFeeEqualsToPercentageOfGrossProceedsFromSaleOfCommonStockAndWarrants" xml:lang="en-US">Cash Fee Equals To Percentage Of Gross Proceeds From Sale Of Common Stock and Warrants</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_CashFeeEqualsToPercentageOfGrossProceedsFromSaleOfCommonStockAndWarrants" xml:lang="en-US">Cash Fee Equals to Percentage of Gross Proceeds from Sale of Common Stock and Warrants</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_CashFeeEqualsToPercentageOfGrossProceedsFromSaleOfCommonStockAndWarrants" xml:lang="en-US">Percentage refers to the value of gross proceeds from sale of common stock and warrants which equals cash fee paid to private placement agent.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_CashFeeEqualsToPercentageOfGrossProceedsFromSaleOfCommonStockAndWarrants" xlink:to="lab_atos_CashFeeEqualsToPercentageOfGrossProceedsFromSaleOfCommonStockAndWarrants" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PaymentsOfStockIssuanceCosts" xlink:label="loc_us-gaap_PaymentsOfStockIssuanceCosts" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_PaymentsOfStockIssuanceCosts" xml:lang="en-US">Payments of Stock Issuance Costs</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_PaymentsOfStockIssuanceCosts" xml:lang="en-US">Fees and Commissions, Other</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsOfStockIssuanceCosts" xlink:to="lab_us-gaap_PaymentsOfStockIssuanceCosts" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_ExercisePriceOfCommonStock" xlink:label="loc_atos_ExercisePriceOfCommonStock" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_ExercisePriceOfCommonStock" xml:lang="en-US">Exercise Price Of Common Stock</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_ExercisePriceOfCommonStock" xml:lang="en-US">Exercise Price of Common Stock</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_ExercisePriceOfCommonStock" xml:lang="en-US">The exercise price of common stock outstanding.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_ExercisePriceOfCommonStock" xlink:to="lab_atos_ExercisePriceOfCommonStock" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_FairValueOfWarrants" xlink:label="loc_atos_FairValueOfWarrants" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_FairValueOfWarrants" xml:lang="en-US">Fair Value Of Warrants</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_FairValueOfWarrants" xml:lang="en-US">Fair Value of Warrants (in dollars per warrant)</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_FairValueOfWarrants" xml:lang="en-US">The fair value of the warrants price of each class of warrants.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_FairValueOfWarrants" xlink:to="lab_atos_FairValueOfWarrants" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_InitialFairValueOfWarrants" xlink:label="loc_atos_InitialFairValueOfWarrants" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_InitialFairValueOfWarrants" xml:lang="en-US">Initial Fair Value Of Warrants</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_InitialFairValueOfWarrants" xml:lang="en-US">Initial Fair Value of Warrants</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_InitialFairValueOfWarrants" xml:lang="en-US">The aggregate initial fair value of the warrants.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_InitialFairValueOfWarrants" xlink:to="lab_atos_InitialFairValueOfWarrants" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" xlink:label="loc_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" xml:lang="en-US">Class of Warrant or Right, Number of Securities Called by Warrants or Rights</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" xlink:to="lab_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SharesIssued" xlink:label="loc_us-gaap_SharesIssued" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SharesIssued" xml:lang="en-US">Shares, Issued</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SharesIssued" xlink:to="lab_us-gaap_SharesIssued" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SharesIssuedPricePerShare" xlink:label="loc_us-gaap_SharesIssuedPricePerShare" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SharesIssuedPricePerShare" xml:lang="en-US">Shares Issued, Price Per Share</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SharesIssuedPricePerShare" xlink:to="lab_us-gaap_SharesIssuedPricePerShare" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ProceedsFromIssuanceInitialPublicOffering" xlink:label="loc_us-gaap_ProceedsFromIssuanceInitialPublicOffering" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ProceedsFromIssuanceInitialPublicOffering" xml:lang="en-US">Proceeds from Issuance Initial Public Offering</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProceedsFromIssuanceInitialPublicOffering" xlink:to="lab_us-gaap_ProceedsFromIssuanceInitialPublicOffering" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockholdersEquityNoteStockSplit" xlink:label="loc_us-gaap_StockholdersEquityNoteStockSplit" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_StockholdersEquityNoteStockSplit" xml:lang="en-US">Stockholders Equity Note, Stock Split</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockholdersEquityNoteStockSplit" xlink:to="lab_us-gaap_StockholdersEquityNoteStockSplit" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_WarrantsCallablePerShare" xlink:label="loc_atos_WarrantsCallablePerShare" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_WarrantsCallablePerShare" xml:lang="en-US">Warrants Callable Per Share</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_WarrantsCallablePerShare" xml:lang="en-US">Warrants Callable Per Share.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_WarrantsCallablePerShare" xlink:to="lab_atos_WarrantsCallablePerShare" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ConcentrationRiskTable" xlink:label="loc_us-gaap_ConcentrationRiskTable" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ConcentrationRiskTable" xml:lang="en-US">Concentration Risk [Table]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ConcentrationRiskTable" xlink:to="lab_us-gaap_ConcentrationRiskTable" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ConcentrationRiskLineItems" xlink:label="loc_us-gaap_ConcentrationRiskLineItems" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ConcentrationRiskLineItems" xml:lang="en-US">Concentration Risk [Line Items]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ConcentrationRiskLineItems" xlink:to="lab_us-gaap_ConcentrationRiskLineItems" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CashFDICInsuredAmount" xlink:label="loc_us-gaap_CashFDICInsuredAmount" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_CashFDICInsuredAmount" xml:lang="en-US">Cash, FDIC Insured Amount</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_CashFDICInsuredAmount" xml:lang="en-US">Cash, FDIC Insured Amount</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CashFDICInsuredAmount" xlink:to="lab_us-gaap_CashFDICInsuredAmount" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CashUninsuredAmount" xlink:label="loc_us-gaap_CashUninsuredAmount" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_CashUninsuredAmount" xml:lang="en-US">Cash, Uninsured Amount</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_CashUninsuredAmount" xml:lang="en-US">Cash, Uninsured Amount</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CashUninsuredAmount" xlink:to="lab_us-gaap_CashUninsuredAmount" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfOperatingLeasedAssetsTable" xlink:label="loc_us-gaap_ScheduleOfOperatingLeasedAssetsTable" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ScheduleOfOperatingLeasedAssetsTable" xml:lang="en-US">Schedule of Operating Leased Assets [Table]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfOperatingLeasedAssetsTable" xlink:to="lab_us-gaap_ScheduleOfOperatingLeasedAssetsTable" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingLeasedAssetsLineItems" xlink:label="loc_us-gaap_OperatingLeasedAssetsLineItems" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_OperatingLeasedAssetsLineItems" xml:lang="en-US">Operating Leased Assets [Line Items]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeasedAssetsLineItems" xlink:to="lab_us-gaap_OperatingLeasedAssetsLineItems" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent" xml:lang="en-US">Operating Leases, Future Minimum Payments Due, Next Twelve Months</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent" xml:lang="en-US">2014 (remainder of the year)</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent" xlink:to="lab_us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xml:lang="en-US">Operating Leases, Future Minimum Payments, Due In Two Years</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xml:lang="en-US">2015</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:to="lab_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears" xml:lang="en-US">Operating Leases, Future Minimum Payments, Due In Three Years</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears" xml:lang="en-US">2016</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears" xlink:to="lab_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears" xml:lang="en-US">Operating Leases, Future Minimum Payments, Due In Four Years</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears" xml:lang="en-US">2017</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears" xlink:to="lab_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDue" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDue" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_OperatingLeasesFutureMinimumPaymentsDue" xml:lang="en-US">Operating Leases, Future Minimum Payments Due, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="lab_us-gaap_OperatingLeasesFutureMinimumPaymentsDue" xml:lang="en-US">Total minimum lease payments</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDue" xlink:to="lab_us-gaap_OperatingLeasesFutureMinimumPaymentsDue" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_CommitmentsAndContingenciesTable" xlink:label="loc_atos_CommitmentsAndContingenciesTable" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_CommitmentsAndContingenciesTable" xml:lang="en-US">COMMITMENTS AND CONTINGENCIES [Table]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_CommitmentsAndContingenciesTable" xlink:to="lab_atos_CommitmentsAndContingenciesTable" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_LeaseAgreement2010Member" xlink:label="loc_atos_LeaseAgreement2010Member" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_LeaseAgreement2010Member" xml:lang="en-US">Lease Agreement 2010 [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_LeaseAgreement2010Member" xlink:to="lab_atos_LeaseAgreement2010Member" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_LeaseAgreementMarch2011Member" xlink:label="loc_atos_LeaseAgreementMarch2011Member" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_LeaseAgreementMarch2011Member" xml:lang="en-US">Lease Agreement March 2011 [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_LeaseAgreementMarch2011Member" xlink:to="lab_atos_LeaseAgreementMarch2011Member" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_LeaseAgreementJuly2011Member" xlink:label="loc_atos_LeaseAgreementJuly2011Member" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_LeaseAgreementJuly2011Member" xml:lang="en-US">Lease Agreement July 2011 [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_LeaseAgreementJuly2011Member" xlink:to="lab_atos_LeaseAgreementJuly2011Member" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_LeaseAgreementSeptember2011Member" xlink:label="loc_atos_LeaseAgreementSeptember2011Member" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_LeaseAgreementSeptember2011Member" xml:lang="en-US">Lease Agreement September 2011 [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_LeaseAgreementSeptember2011Member" xlink:to="lab_atos_LeaseAgreementSeptember2011Member" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_LeaseAgreementMarch2014Member" xlink:label="loc_atos_LeaseAgreementMarch2014Member" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_LeaseAgreementMarch2014Member" xml:lang="en-US">Lease Agreement March 2014 [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_LeaseAgreementMarch2014Member" xlink:to="lab_atos_LeaseAgreementMarch2014Member" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_ComplegenIncMember" xlink:label="loc_atos_ComplegenIncMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_ComplegenIncMember" xml:lang="en-US">Complegen Inc [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_ComplegenIncMember" xml:lang="en-US">CompleGen [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_ComplegenIncMember" xlink:to="lab_atos_ComplegenIncMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_SandersPropertiesLlcMember" xlink:label="loc_atos_SandersPropertiesLlcMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_SandersPropertiesLlcMember" xml:lang="en-US">Sanders Properties, Llc [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_SandersPropertiesLlcMember" xlink:to="lab_atos_SandersPropertiesLlcMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_FredHutchinsonResearchCenterMember" xlink:label="loc_atos_FredHutchinsonResearchCenterMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_FredHutchinsonResearchCenterMember" xml:lang="en-US">Fred Hutchinson Research Center [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_FredHutchinsonResearchCenterMember" xlink:to="lab_atos_FredHutchinsonResearchCenterMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_RobertKellyMember" xlink:label="loc_atos_RobertKellyMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_RobertKellyMember" xml:lang="en-US">Robert Kelly [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_RobertKellyMember" xlink:to="lab_atos_RobertKellyMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_MonthlyRentAxis" xlink:label="loc_atos_MonthlyRentAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_MonthlyRentAxis" xml:lang="en-US">Monthly Rent [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_MonthlyRentAxis" xlink:to="lab_atos_MonthlyRentAxis" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_MonthlyRentDomain" xlink:label="loc_atos_MonthlyRentDomain" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_MonthlyRentDomain" xml:lang="en-US">Monthly Rent [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_MonthlyRentDomain" xlink:to="lab_atos_MonthlyRentDomain" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_MonthlyRentForPeriodFromFebruary242012ToAugust312012Member" xlink:label="loc_atos_MonthlyRentForPeriodFromFebruary242012ToAugust312012Member" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_MonthlyRentForPeriodFromFebruary242012ToAugust312012Member" xml:lang="en-US">Monthly Rent For Period From February 24, 2012 To August 31, 2012 [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_MonthlyRentForPeriodFromFebruary242012ToAugust312012Member" xlink:to="lab_atos_MonthlyRentForPeriodFromFebruary242012ToAugust312012Member" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_MonthlyRentForPeriodFromSeptember12012ToAugust312013Member" xlink:label="loc_atos_MonthlyRentForPeriodFromSeptember12012ToAugust312013Member" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_MonthlyRentForPeriodFromSeptember12012ToAugust312013Member" xml:lang="en-US">Monthly Rent For Period From September 1, 2012 To August 31, 2013 [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_MonthlyRentForPeriodFromSeptember12012ToAugust312013Member" xlink:to="lab_atos_MonthlyRentForPeriodFromSeptember12012ToAugust312013Member" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_MonthlyRentForPeriodFromSeptember12013ToNovember292014Member" xlink:label="loc_atos_MonthlyRentForPeriodFromSeptember12013ToNovember292014Member" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_MonthlyRentForPeriodFromSeptember12013ToNovember292014Member" xml:lang="en-US">Monthly Rent For Period From September 1, 2013 To November 29, 2014 [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_MonthlyRentForPeriodFromSeptember12013ToNovember292014Member" xlink:to="lab_atos_MonthlyRentForPeriodFromSeptember12013ToNovember292014Member" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_MonthlyRentFromDecember2014ThroughNovember2015Member" xlink:label="loc_atos_MonthlyRentFromDecember2014ThroughNovember2015Member" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_MonthlyRentFromDecember2014ThroughNovember2015Member" xml:lang="en-US">Monthly Rent From December 2014 Through November 2015 [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_MonthlyRentFromDecember2014ThroughNovember2015Member" xlink:to="lab_atos_MonthlyRentFromDecember2014ThroughNovember2015Member" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_MonthlyRentFromDecember2015ThroughNovember2016Member" xlink:label="loc_atos_MonthlyRentFromDecember2015ThroughNovember2016Member" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_MonthlyRentFromDecember2015ThroughNovember2016Member" xml:lang="en-US">Monthly Rent From December 2015 Through November 2016 [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_MonthlyRentFromDecember2015ThroughNovember2016Member" xlink:to="lab_atos_MonthlyRentFromDecember2015ThroughNovember2016Member" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PurchaseCommitmentExcludingLongtermCommitmentAxis" xlink:label="loc_us-gaap_PurchaseCommitmentExcludingLongtermCommitmentAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_PurchaseCommitmentExcludingLongtermCommitmentAxis" xml:lang="en-US">Purchase Commitment, Excluding Long-term Commitment [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PurchaseCommitmentExcludingLongtermCommitmentAxis" xlink:to="lab_us-gaap_PurchaseCommitmentExcludingLongtermCommitmentAxis" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PurchaseCommitmentExcludingLongtermCommitmentDomain" xlink:label="loc_us-gaap_PurchaseCommitmentExcludingLongtermCommitmentDomain" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_PurchaseCommitmentExcludingLongtermCommitmentDomain" xml:lang="en-US">Purchase Commitment, Excluding Long-term Commitment [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PurchaseCommitmentExcludingLongtermCommitmentDomain" xlink:to="lab_us-gaap_PurchaseCommitmentExcludingLongtermCommitmentDomain" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_AffymetrixInMember" xlink:label="loc_atos_AffymetrixInMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_AffymetrixInMember" xml:lang="en-US">Affymetrix In [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_AffymetrixInMember" xlink:to="lab_atos_AffymetrixInMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_LeaseAgreementAxis" xlink:label="loc_atos_LeaseAgreementAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_LeaseAgreementAxis" xml:lang="en-US">Lease Agreement [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_LeaseAgreementAxis" xlink:to="lab_atos_LeaseAgreementAxis" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_LeaseAgreementDomain" xlink:label="loc_atos_LeaseAgreementDomain" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_LeaseAgreementDomain" xml:lang="en-US">Lease Agreement [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_LeaseAgreementDomain" xlink:to="lab_atos_LeaseAgreementDomain" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_OwnerchipProgramAgreementMember" xlink:label="loc_atos_OwnerchipProgramAgreementMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_OwnerchipProgramAgreementMember" xml:lang="en-US">OwnerChip Program Agreement [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_OwnerchipProgramAgreementMember" xlink:to="lab_atos_OwnerchipProgramAgreementMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_dei_LegalEntityAxis" xml:lang="en-US">Legal Entity [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_LegalEntityAxis" xlink:to="lab_dei_LegalEntityAxis" />

    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_dei_EntityDomain" xml:lang="en-US">Entity [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityDomain" xlink:to="lab_dei_EntityDomain" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_A5GeneticsKftMember" xlink:label="loc_atos_A5GeneticsKftMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_A5GeneticsKftMember" xml:lang="en-US">A5 Genetics KFT [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_A5GeneticsKftMember" xlink:to="lab_atos_A5GeneticsKftMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="loc_us-gaap_SubsequentEventMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SubsequentEventMember" xml:lang="en-US">Subsequent Event [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubsequentEventMember" xlink:to="lab_us-gaap_SubsequentEventMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_CommitmentsAndContingenciesLineItems" xlink:label="loc_atos_CommitmentsAndContingenciesLineItems" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_CommitmentsAndContingenciesLineItems" xml:lang="en-US">COMMITMENTS AND CONTINGENCIES [Line Items]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_CommitmentsAndContingenciesLineItems" xlink:to="lab_atos_CommitmentsAndContingenciesLineItems" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LossContingencyDamagesSoughtValue" xlink:label="loc_us-gaap_LossContingencyDamagesSoughtValue" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_LossContingencyDamagesSoughtValue" xml:lang="en-US">Loss Contingency, Damages Sought, Value</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_LossContingencyDamagesSoughtValue" xml:lang="en-US">Loss Contingency, Damages Sought, Value</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LossContingencyDamagesSoughtValue" xlink:to="lab_us-gaap_LossContingencyDamagesSoughtValue" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PaymentsForSoftware" xlink:label="loc_us-gaap_PaymentsForSoftware" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_PaymentsForSoftware" xml:lang="en-US">Payments for Software, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_PaymentsForSoftware" xml:lang="en-US">Payments for Software</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsForSoftware" xlink:to="lab_us-gaap_PaymentsForSoftware" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PurchaseObligation" xlink:label="loc_us-gaap_PurchaseObligation" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_PurchaseObligation" xml:lang="en-US">Purchase Obligation, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_PurchaseObligation" xml:lang="en-US">Purchase Obligation</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PurchaseObligation" xlink:to="lab_us-gaap_PurchaseObligation" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ContractReceivableDueInRollingYearTwo" xlink:label="loc_us-gaap_ContractReceivableDueInRollingYearTwo" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ContractReceivableDueInRollingYearTwo" xml:lang="en-US">Contract Receivable, Due in Rolling Year Two</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ContractReceivableDueInRollingYearTwo" xlink:to="lab_us-gaap_ContractReceivableDueInRollingYearTwo" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_AgreedToForfeit" xlink:label="loc_atos_AgreedToForfeit" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_AgreedToForfeit" xml:lang="en-US">Agreed To Forfeit</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_AgreedToForfeit" xml:lang="en-US">Company agreed to forfeit and separately pay in restitution.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_AgreedToForfeit" xlink:to="lab_atos_AgreedToForfeit" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_RecallExpensesActual" xlink:label="loc_atos_RecallExpensesActual" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_RecallExpensesActual" xml:lang="en-US">Recall expenses Actual</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_RecallExpensesActual" xml:lang="en-US">Amount of recall expenses actual.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_RecallExpensesActual" xlink:to="lab_atos_RecallExpensesActual" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CostOfServicesLicensesAndServices" xlink:label="loc_us-gaap_CostOfServicesLicensesAndServices" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_CostOfServicesLicensesAndServices" xml:lang="en-US">Cost of Services, Licenses and Services</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CostOfServicesLicensesAndServices" xlink:to="lab_us-gaap_CostOfServicesLicensesAndServices" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_AdditionalLicenseFeeAmountPaid" xlink:label="loc_atos_AdditionalLicenseFeeAmountPaid" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_AdditionalLicenseFeeAmountPaid" xml:lang="en-US">Additional License Fee Amount Paid</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_AdditionalLicenseFeeAmountPaid" xml:lang="en-US">Costs incurred for development of computer software, which is to be leased or otherwise marketed, after establishing technological feasibility through to the general release of the software products during the reporting period.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_AdditionalLicenseFeeAmountPaid" xlink:to="lab_atos_AdditionalLicenseFeeAmountPaid" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_AdditionalLicenseFeeObligationToPayForFutureMilestones" xlink:label="loc_atos_AdditionalLicenseFeeObligationToPayForFutureMilestones" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_AdditionalLicenseFeeObligationToPayForFutureMilestones" xml:lang="en-US">Additional License Fee Obligation To Pay For Future Milestones</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_AdditionalLicenseFeeObligationToPayForFutureMilestones" xml:lang="en-US">Additional license fee obligation to pay for achievement of future milestones.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_AdditionalLicenseFeeObligationToPayForFutureMilestones" xlink:to="lab_atos_AdditionalLicenseFeeObligationToPayForFutureMilestones" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_RoyaltyExpense" xlink:label="loc_us-gaap_RoyaltyExpense" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_RoyaltyExpense" xml:lang="en-US">Royalty Expense</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RoyaltyExpense" xlink:to="lab_us-gaap_RoyaltyExpense" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_ShareBasedPaymentAwardStockOptionsValuationAssumptionTable" xlink:label="loc_atos_ShareBasedPaymentAwardStockOptionsValuationAssumptionTable" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_ShareBasedPaymentAwardStockOptionsValuationAssumptionTable" xml:lang="en-US">Share Based Payment Award Stock Options Valuation Assumption [Table]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_ShareBasedPaymentAwardStockOptionsValuationAssumptionTable" xlink:to="lab_atos_ShareBasedPaymentAwardStockOptionsValuationAssumptionTable" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_DrHunkapillerMember" xlink:label="loc_atos_DrHunkapillerMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_DrHunkapillerMember" xml:lang="en-US">Dr Hunkapiller [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_DrHunkapillerMember" xml:lang="en-US">Dr.Hunkapiller [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_DrHunkapillerMember" xlink:to="lab_atos_DrHunkapillerMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_EmployeesMember" xlink:label="loc_atos_EmployeesMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_EmployeesMember" xml:lang="en-US">Employees [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_EmployeesMember" xlink:to="lab_atos_EmployeesMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_OfficersMember" xlink:label="loc_atos_OfficersMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_OfficersMember" xml:lang="en-US">Officers [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_OfficersMember" xlink:to="lab_atos_OfficersMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_DirectorsMember" xlink:label="loc_atos_DirectorsMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_DirectorsMember" xml:lang="en-US">Directors [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_DirectorsMember" xml:lang="en-US">Non-Employee Director [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_DirectorsMember" xlink:to="lab_atos_DirectorsMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_ChiefExecutiveOfficerAndChiefScientificOfficerMember" xlink:label="loc_atos_ChiefExecutiveOfficerAndChiefScientificOfficerMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_ChiefExecutiveOfficerAndChiefScientificOfficerMember" xml:lang="en-US">Chief Executive Officer and Chief Scientific Officer [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_ChiefExecutiveOfficerAndChiefScientificOfficerMember" xlink:to="lab_atos_ChiefExecutiveOfficerAndChiefScientificOfficerMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_StockOptionOneMember" xlink:label="loc_atos_StockOptionOneMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_StockOptionOneMember" xml:lang="en-US">Stock Option One [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_StockOptionOneMember" xml:lang="en-US">Stock Option [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_StockOptionOneMember" xlink:to="lab_atos_StockOptionOneMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_StockOptionTwoMember" xlink:label="loc_atos_StockOptionTwoMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_StockOptionTwoMember" xml:lang="en-US">Stock Option Two [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_StockOptionTwoMember" xml:lang="en-US">Stock Option [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_StockOptionTwoMember" xlink:to="lab_atos_StockOptionTwoMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_StockOptionThreeMember" xlink:label="loc_atos_StockOptionThreeMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_StockOptionThreeMember" xml:lang="en-US">Stock Option Three [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_StockOptionThreeMember" xml:lang="en-US">Stock Option [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_StockOptionThreeMember" xlink:to="lab_atos_StockOptionThreeMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_ShareBasedPaymentAwardStockOptionsValuationAssumptionLineItems" xlink:label="loc_atos_ShareBasedPaymentAwardStockOptionsValuationAssumptionLineItems" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_ShareBasedPaymentAwardStockOptionsValuationAssumptionLineItems" xml:lang="en-US">Share Based Payment Award Stock Options Valuation Assumption [Line Items]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_ShareBasedPaymentAwardStockOptionsValuationAssumptionLineItems" xlink:to="lab_atos_ShareBasedPaymentAwardStockOptionsValuationAssumptionLineItems" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantDate" xlink:label="loc_atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantDate" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantDate" xml:lang="en-US">Share Based Compensation Arrangement By Share Based Payment Award Options Grant Date</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantDate" xml:lang="en-US">Date of grant</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantDate" xml:lang="en-US">Date the equity-based award granted, in CCYY-MM-DD format.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantDate" xlink:to="lab_atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantDate" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_RelatedPartyTransactionDateRangeStart" xlink:label="loc_atos_RelatedPartyTransactionDateRangeStart" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_RelatedPartyTransactionDateRangeStart" xml:lang="en-US">Related Party Transaction Date Range Start</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_atos_RelatedPartyTransactionDateRangeStart" xml:lang="en-US">Date of grant start</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_RelatedPartyTransactionDateRangeStart" xml:lang="en-US">Date the equity-based award granted start range, in CCYY-MM-DD format.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_RelatedPartyTransactionDateRangeStart" xlink:to="lab_atos_RelatedPartyTransactionDateRangeStart" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_RelatedPartyTransactionDateRangeEnd" xlink:label="loc_atos_RelatedPartyTransactionDateRangeEnd" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_RelatedPartyTransactionDateRangeEnd" xml:lang="en-US">Related Party Transaction Date Range End</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_RelatedPartyTransactionDateRangeEnd" xml:lang="en-US">Date of grant end</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_RelatedPartyTransactionDateRangeEnd" xml:lang="en-US">Date the equity-based award granted end range, in CCYY-MM-DD format.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_RelatedPartyTransactionDateRangeEnd" xlink:to="lab_atos_RelatedPartyTransactionDateRangeEnd" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xml:lang="en-US">Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Grants In Period, Weighted Average Grant Date Fair Value</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xml:lang="en-US">Fair value of common stock on date of grant</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xml:lang="en-US">Share-Based Compensation Arrangement By Share-Based Payment Award, Fair Value Assumptions, Expected Dividend Rate</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xml:lang="en-US">Dividend yield</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xml:lang="en-US">Share-Based Compensation Arrangement By Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xml:lang="en-US">Risk free rate</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xml:lang="en-US">Risk-free interest rate</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedForfeitureRate" xlink:label="loc_atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedForfeitureRate" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedForfeitureRate" xml:lang="en-US">Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Forfeiture Rate</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedForfeitureRate" xml:lang="en-US">Expected forfeiture per year (%)</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedForfeitureRate" xml:lang="en-US">The estimated measure of the percentage by which the options are expected to be forfeited during the period.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedForfeitureRate" xlink:to="lab_atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedForfeitureRate" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageFairValue" xlink:label="loc_atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageFairValue" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageFairValue" xml:lang="en-US">Share Based Compensation Arrangement By Share Based Payment Award Options Weighted Average Fair Value</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageFairValue" xml:lang="en-US">Weighted-average fair value of the options (per unit)</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageFairValue" xml:lang="en-US">The weighted average fair value of the options.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageFairValue" xlink:to="lab_atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageFairValue" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_ShareBasedCompensationStockOptionsActivityTable" xlink:label="loc_atos_ShareBasedCompensationStockOptionsActivityTable" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_ShareBasedCompensationStockOptionsActivityTable" xml:lang="en-US">Share Based Compensation Stock Options Activity [Table]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_ShareBasedCompensationStockOptionsActivityTable" xlink:to="lab_atos_ShareBasedCompensationStockOptionsActivityTable" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_ShareBasedCompensationStockOptionsActivityLineItems" xlink:label="loc_atos_ShareBasedCompensationStockOptionsActivityLineItems" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_ShareBasedCompensationStockOptionsActivityLineItems" xml:lang="en-US">Share Based Compensation Stock Options Activity [Line Items]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_ShareBasedCompensationStockOptionsActivityLineItems" xlink:to="lab_atos_ShareBasedCompensationStockOptionsActivityLineItems" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Beginning Balance</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xml:lang="en-US">Number of Underlying Shares, Outstanding as of January 1, 2014 (in shares)</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xml:lang="en-US">Number of Underlying Shares, Outstanding as of June 30, 2014 (in shares)</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xml:lang="en-US">Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Grants In Period, Gross</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xml:lang="en-US">Number of Underlying Shares, Granted (in shares)</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/presentationGuidance" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xml:lang="en-US">Stock option grant</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xml:lang="en-US">Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Forfeitures In Period</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xml:lang="en-US">Number of Underlying Shares, Forfeited (in shares)</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_StockIssuedDuringPeriodSharesStockOptionsExercised1" xlink:label="loc_atos_StockIssuedDuringPeriodSharesStockOptionsExercised1" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_StockIssuedDuringPeriodSharesStockOptionsExercised1" xml:lang="en-US">Stock Issued During Period, Shares, Stock Options Exercised1</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="lab_atos_StockIssuedDuringPeriodSharesStockOptionsExercised1" xml:lang="en-US">Number of Underlying Shares, Exercised (in shares)</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_StockIssuedDuringPeriodSharesStockOptionsExercised1" xml:lang="en-US">Number of share options (or share units) exercised during the current period.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_StockIssuedDuringPeriodSharesStockOptionsExercised1" xlink:to="lab_atos_StockIssuedDuringPeriodSharesStockOptionsExercised1" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xml:lang="en-US">Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Exercisable, Number</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xml:lang="en-US">Number of Underlying Shares, Exercisable as of June 30, 2014 (in shares)</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" xml:lang="en-US">Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Vested and Expected To Vest, Outstanding, Number</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" xml:lang="en-US">Number of Underlying Shares, Vested and expected to vest (in shares)</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xml:lang="en-US">Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xml:lang="en-US">Weighted-Average Exercise Price Per Share, Outstanding as of January 1, 2014 (in dollars per share)</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xml:lang="en-US">Weighted-Average Exercise Price Per Share, Outstanding as of June 30, 2014 (in dollars per share)</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xml:lang="en-US">Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xml:lang="en-US">Weighted-Average Exercise Price Per Share, Granted (in dollars per share)</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xml:lang="en-US">Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" xml:lang="en-US">Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" xml:lang="en-US">Weighted-Average Exercise Price Per Share, Forfeited (in dollars per share)</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xml:lang="en-US">Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xml:lang="en-US">Weighted-Average Exercise Price Per Share, Exercised (in dollars per share)</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xml:lang="en-US">Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Exercisable, Weighted Average Exercise Price</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xml:lang="en-US">Weighted-Average Exercise Price Per Share, Exercisable as of June 30, 2014 (in dollars per share)</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" xml:lang="en-US">Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Vested and Expected To Vest, Outstanding, Weighted Average Exercise Price</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" xml:lang="en-US">Weighted-Average Exercise Price Per Share, Vested and expected to vest (in dollars per share)</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xml:lang="en-US">Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xml:lang="en-US">Weighted-Average Contractual Life Remaining in Years, Outstanding as of June 30, 2014</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:to="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xml:lang="en-US">Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xml:lang="en-US">Weighted-Average Contractual Life Remaining in Years, Exercisable as of as of June 30, 2014</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:to="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" xml:lang="en-US">Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Vested and Expected To Vest, Outstanding, Weighted Average Remaining Contractual Term</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" xml:lang="en-US">Weighted-Average Contractual Life Remaining in Years, Vested and expected to vest</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" xlink:to="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xml:lang="en-US">Aggregate Intrinsic Value, Outstanding as of January 1, 2014</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xml:lang="en-US">Aggregate Intrinsic Value, Outstanding as of June 30, 2014</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeitedInPeriodTotalIntrinsicValue" xlink:label="loc_atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeitedInPeriodTotalIntrinsicValue" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeitedInPeriodTotalIntrinsicValue" xml:lang="en-US">Share Based Compensation Arrangement By Share Based Payment Award Options Forfeited In Period Total Intrinsic Value</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeitedInPeriodTotalIntrinsicValue" xml:lang="en-US">Aggregate Intrinsic Value, Forfeited (in dollars)</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeitedInPeriodTotalIntrinsicValue" xml:lang="en-US">Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options forfeited (or share units converted) into shares.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeitedInPeriodTotalIntrinsicValue" xlink:to="lab_atos_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeitedInPeriodTotalIntrinsicValue" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_StockbasedCompensationTable" xlink:label="loc_atos_StockbasedCompensationTable" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_StockbasedCompensationTable" xml:lang="en-US">Stock-based Compensation [Table]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_StockbasedCompensationTable" xlink:to="lab_atos_StockbasedCompensationTable" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_BoardOfDirectorsChairmanAndChiefExecutiveOfficeMember" xlink:label="loc_atos_BoardOfDirectorsChairmanAndChiefExecutiveOfficeMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_BoardOfDirectorsChairmanAndChiefExecutiveOfficeMember" xml:lang="en-US">Board Of Directors Chairman and Chief Executive Office [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_BoardOfDirectorsChairmanAndChiefExecutiveOfficeMember" xlink:to="lab_atos_BoardOfDirectorsChairmanAndChiefExecutiveOfficeMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_FormerPresidentMember" xlink:label="loc_atos_FormerPresidentMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_FormerPresidentMember" xml:lang="en-US">Former President [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_FormerPresidentMember" xlink:to="lab_atos_FormerPresidentMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_ChiefScientificOfficerMember" xlink:label="loc_atos_ChiefScientificOfficerMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_ChiefScientificOfficerMember" xml:lang="en-US">Chief Scientific Officer [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_ChiefScientificOfficerMember" xlink:to="lab_atos_ChiefScientificOfficerMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_ChiefExecutiveOfficerAndChiefTechnologyOfficerMember" xlink:label="loc_atos_ChiefExecutiveOfficerAndChiefTechnologyOfficerMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_ChiefExecutiveOfficerAndChiefTechnologyOfficerMember" xml:lang="en-US">Chief Executive Officer And Chief Technology Officer [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_ChiefExecutiveOfficerAndChiefTechnologyOfficerMember" xml:lang="en-US">Chief Executive Officer and Chief Technology Officer [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_ChiefExecutiveOfficerAndChiefTechnologyOfficerMember" xlink:to="lab_atos_ChiefExecutiveOfficerAndChiefTechnologyOfficerMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BoardOfDirectorsChairmanMember" xlink:label="loc_us-gaap_BoardOfDirectorsChairmanMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_BoardOfDirectorsChairmanMember" xml:lang="en-US">Board of Directors Chairman [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BoardOfDirectorsChairmanMember" xlink:to="lab_us-gaap_BoardOfDirectorsChairmanMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_DebtInstrumentAxis" xml:lang="en-US">Debt Instrument [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentAxis" xlink:to="lab_us-gaap_DebtInstrumentAxis" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_DebtInstrumentNameDomain" xml:lang="en-US">Debt Instrument, Name [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="lab_us-gaap_DebtInstrumentNameDomain" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_PromissoryNoteOneMember" xlink:label="loc_atos_PromissoryNoteOneMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_PromissoryNoteOneMember" xml:lang="en-US">Promissory Note One [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_PromissoryNoteOneMember" xlink:to="lab_atos_PromissoryNoteOneMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_PromissoryNoteTwoMember" xlink:label="loc_atos_PromissoryNoteTwoMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_PromissoryNoteTwoMember" xml:lang="en-US">Promissory Note Two [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_PromissoryNoteTwoMember" xlink:to="lab_atos_PromissoryNoteTwoMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_RobertLKellyMember" xlink:label="loc_atos_RobertLKellyMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_RobertLKellyMember" xml:lang="en-US">Robert L Kelly [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_RobertLKellyMember" xml:lang="en-US">Robert L.Kelly [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_RobertLKellyMember" xlink:to="lab_atos_RobertLKellyMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_IncomeStatementLocationAxis" xml:lang="en-US">Income Statement Location [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeStatementLocationAxis" xlink:to="lab_us-gaap_IncomeStatementLocationAxis" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_IncomeStatementLocationDomain" xml:lang="en-US">Income Statement Location [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeStatementLocationDomain" xlink:to="lab_us-gaap_IncomeStatementLocationDomain" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ResearchAndDevelopmentExpenseMember" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpenseMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ResearchAndDevelopmentExpenseMember" xml:lang="en-US">Research and Development Expense [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ResearchAndDevelopmentExpenseMember" xlink:to="lab_us-gaap_ResearchAndDevelopmentExpenseMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_ReverseStockSplitAxis" xlink:label="loc_atos_ReverseStockSplitAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_ReverseStockSplitAxis" xml:lang="en-US">Reverse Stock Split [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_ReverseStockSplitAxis" xlink:to="lab_atos_ReverseStockSplitAxis" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_ReverseStockSplitDomain" xlink:label="loc_atos_ReverseStockSplitDomain" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_ReverseStockSplitDomain" xml:lang="en-US">Reverse Stock Split [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_ReverseStockSplitDomain" xlink:to="lab_atos_ReverseStockSplitDomain" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_PriorToReverseStockSplitMember" xlink:label="loc_atos_PriorToReverseStockSplitMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_PriorToReverseStockSplitMember" xml:lang="en-US">Prior To Reverse Stock Split [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_PriorToReverseStockSplitMember" xml:lang="en-US">Prior to Reverse Stock Split [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_PriorToReverseStockSplitMember" xlink:to="lab_atos_PriorToReverseStockSplitMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_NonQualifiedStockOptionsWereGrantedUnder2010PlanMember" xlink:label="loc_atos_NonQualifiedStockOptionsWereGrantedUnder2010PlanMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_NonQualifiedStockOptionsWereGrantedUnder2010PlanMember" xml:lang="en-US">Non Qualified Stock Options Were Granted Under 2010 Plan [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_NonQualifiedStockOptionsWereGrantedUnder2010PlanMember" xml:lang="en-US">Non-Qualified Stock Options Were Granted Under The 2010 Plan [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_NonQualifiedStockOptionsWereGrantedUnder2010PlanMember" xlink:to="lab_atos_NonQualifiedStockOptionsWereGrantedUnder2010PlanMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_StockOptionsWereGrantedOutsideOf2010PlanMember" xlink:label="loc_atos_StockOptionsWereGrantedOutsideOf2010PlanMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_StockOptionsWereGrantedOutsideOf2010PlanMember" xml:lang="en-US">Stock Options Were Granted Outside Of 2010 Plan [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_StockOptionsWereGrantedOutsideOf2010PlanMember" xlink:to="lab_atos_StockOptionsWereGrantedOutsideOf2010PlanMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_StockbasedCompensationLineItems" xlink:label="loc_atos_StockbasedCompensationLineItems" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_StockbasedCompensationLineItems" xml:lang="en-US">Stock-based Compensation [Line Items]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_StockbasedCompensationLineItems" xlink:to="lab_atos_StockbasedCompensationLineItems" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross" xml:lang="en-US">Stock Issued During Period, Shares, Restricted Stock Award, Gross</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross" xlink:to="lab_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross" xml:lang="en-US">Stock Issued During Period, Value, Restricted Stock Award, Gross</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross" xlink:to="lab_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:label="loc_us-gaap_ShareBasedCompensation" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensation" xml:lang="en-US">Share-based Compensation, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_ShareBasedCompensation" xml:lang="en-US">Share-based Compensation</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_ShareBasedCompensation" xml:lang="en-US">Compensation cost for stock options granted</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensation" xlink:to="lab_us-gaap_ShareBasedCompensation" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SubsequentEventTable" xlink:label="loc_us-gaap_SubsequentEventTable" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SubsequentEventTable" xml:lang="en-US">Subsequent Event [Table]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubsequentEventTable" xlink:to="lab_us-gaap_SubsequentEventTable" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_PeriodTypeAxis" xlink:label="loc_atos_PeriodTypeAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_PeriodTypeAxis" xml:lang="en-US">Period Type [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_PeriodTypeAxis" xlink:to="lab_atos_PeriodTypeAxis" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_PeriodTypeDomain" xlink:label="loc_atos_PeriodTypeDomain" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_PeriodTypeDomain" xml:lang="en-US">Period Type [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_PeriodTypeDomain" xlink:to="lab_atos_PeriodTypeDomain" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_FromApril12013ThroughDateOfThisReportMember" xlink:label="loc_atos_FromApril12013ThroughDateOfThisReportMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_FromApril12013ThroughDateOfThisReportMember" xml:lang="en-US">From April 1 2013 Through Date Of This Report [Member]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_FromApril12013ThroughDateOfThisReportMember" xml:lang="en-US">From April 1 2013 Through Date Of This Report [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_FromApril12013ThroughDateOfThisReportMember" xlink:to="lab_atos_FromApril12013ThroughDateOfThisReportMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_April302013Member" xlink:label="loc_atos_April302013Member" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_April302013Member" xml:lang="en-US">April 30, 2013 [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_April302013Member" xlink:to="lab_atos_April302013Member" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ReinsurancePremiumsForInsuranceCompaniesByProductSegmentAxis" xlink:label="loc_us-gaap_ReinsurancePremiumsForInsuranceCompaniesByProductSegmentAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ReinsurancePremiumsForInsuranceCompaniesByProductSegmentAxis" xml:lang="en-US">Insurance Product Line [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ReinsurancePremiumsForInsuranceCompaniesByProductSegmentAxis" xlink:to="lab_us-gaap_ReinsurancePremiumsForInsuranceCompaniesByProductSegmentAxis" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ReinsurancePremiumsForInsuranceCompaniesByProductSegmentDomain" xlink:label="loc_us-gaap_ReinsurancePremiumsForInsuranceCompaniesByProductSegmentDomain" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ReinsurancePremiumsForInsuranceCompaniesByProductSegmentDomain" xml:lang="en-US">Insurance Product Line [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ReinsurancePremiumsForInsuranceCompaniesByProductSegmentDomain" xlink:to="lab_us-gaap_ReinsurancePremiumsForInsuranceCompaniesByProductSegmentDomain" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_MillenniumMedicalDevicesLlcMember" xlink:label="loc_atos_MillenniumMedicalDevicesLlcMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_MillenniumMedicalDevicesLlcMember" xml:lang="en-US">Millennium Medical Devices Llc [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_MillenniumMedicalDevicesLlcMember" xlink:to="lab_atos_MillenniumMedicalDevicesLlcMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementOfCashFlowsAbstract" xlink:label="loc_us-gaap_StatementOfCashFlowsAbstract" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_StatementOfCashFlowsAbstract" xml:lang="en-US">Statement Of Cash Flows [Abstract]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementOfCashFlowsAbstract" xlink:to="lab_us-gaap_StatementOfCashFlowsAbstract" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xml:lang="en-US">Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xml:lang="en-US">CASH FLOWS FROM OPERATING ACTIVITIES</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ProfitLoss" xlink:label="loc_us-gaap_ProfitLoss" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ProfitLoss" xml:lang="en-US">Net Income (Loss), Including Portion Attributable to Noncontrolling Interest, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/definitionGuidance" xlink:label="lab_us-gaap_ProfitLoss" xml:lang="en-US">Net loss</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProfitLoss" xlink:to="lab_us-gaap_ProfitLoss" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueIssuedForServices" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueIssuedForServices" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_StockIssuedDuringPeriodValueIssuedForServices" xml:lang="en-US">Stock Issued During Period, Value, Issued for Services</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="lab_us-gaap_StockIssuedDuringPeriodValueIssuedForServices" xml:lang="en-US">Common shares issued for services</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_StockIssuedDuringPeriodValueIssuedForServices" xml:lang="en-US">Issuance of common shares for services</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockIssuedDuringPeriodValueIssuedForServices" xlink:to="lab_us-gaap_StockIssuedDuringPeriodValueIssuedForServices" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_InventoryWriteDown" xlink:label="loc_us-gaap_InventoryWriteDown" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_InventoryWriteDown" xml:lang="en-US">Inventory Write-down</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/definitionGuidance" xlink:label="lab_us-gaap_InventoryWriteDown" xml:lang="en-US">Inventory Write-downs</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InventoryWriteDown" xlink:to="lab_us-gaap_InventoryWriteDown" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_DepreciationDepletionAndAmortization" xml:lang="en-US">Depreciation, Depletion and Amortization, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_DepreciationDepletionAndAmortization" xml:lang="en-US">Depreciation and amortization</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DepreciationDepletionAndAmortization" xlink:to="lab_us-gaap_DepreciationDepletionAndAmortization" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ProvisionForDoubtfulAccounts" xlink:label="loc_us-gaap_ProvisionForDoubtfulAccounts" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ProvisionForDoubtfulAccounts" xml:lang="en-US">Provision for Doubtful Accounts</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_ProvisionForDoubtfulAccounts" xml:lang="en-US">Bad debt expense</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProvisionForDoubtfulAccounts" xlink:to="lab_us-gaap_ProvisionForDoubtfulAccounts" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xml:lang="en-US">Adjustments To Reconcile Net Income (Loss) To Cash Provided By (Used In) Operating Activities [Abstract]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xml:lang="en-US">Adjustments to reconcile net loss to net cash used in operating activities:</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="lab_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivable" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_IncreaseDecreaseInAccountsReceivable" xml:lang="en-US">Increase (Decrease) In Accounts Receivable</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="lab_us-gaap_IncreaseDecreaseInAccountsReceivable" xml:lang="en-US">Accounts receivable</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:to="lab_us-gaap_IncreaseDecreaseInAccountsReceivable" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncreaseDecreaseInInventories" xlink:label="loc_us-gaap_IncreaseDecreaseInInventories" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_IncreaseDecreaseInInventories" xml:lang="en-US">Increase (Decrease) in Inventories, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="lab_us-gaap_IncreaseDecreaseInInventories" xml:lang="en-US">Inventory</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInInventories" xlink:to="lab_us-gaap_IncreaseDecreaseInInventories" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncreaseDecreaseInPrepaidExpense" xlink:label="loc_us-gaap_IncreaseDecreaseInPrepaidExpense" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_IncreaseDecreaseInPrepaidExpense" xml:lang="en-US">Increase (Decrease) In Prepaid Expense</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="lab_us-gaap_IncreaseDecreaseInPrepaidExpense" xml:lang="en-US">Prepaid expenses</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInPrepaidExpense" xlink:to="lab_us-gaap_IncreaseDecreaseInPrepaidExpense" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncreaseDecreaseInSecurityDeposits" xlink:label="loc_us-gaap_IncreaseDecreaseInSecurityDeposits" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_IncreaseDecreaseInSecurityDeposits" xml:lang="en-US">Increase (Decrease) In Security Deposits</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_IncreaseDecreaseInSecurityDeposits" xml:lang="en-US">Security deposits</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInSecurityDeposits" xlink:to="lab_us-gaap_IncreaseDecreaseInSecurityDeposits" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayable" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayable" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_IncreaseDecreaseInAccountsPayable" xml:lang="en-US">Increase (Decrease) in Accounts Payable, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_IncreaseDecreaseInAccountsPayable" xml:lang="en-US">Accounts payable</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInAccountsPayable" xlink:to="lab_us-gaap_IncreaseDecreaseInAccountsPayable" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities" xlink:label="loc_us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities" xml:lang="en-US">Increase (Decrease) in Employee Related Liabilities</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities" xml:lang="en-US">Payroll liabilities</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities" xlink:to="lab_us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_IncreaseDecreaseInDeferredRent" xlink:label="loc_atos_IncreaseDecreaseInDeferredRent" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_IncreaseDecreaseInDeferredRent" xml:lang="en-US">Increase Decrease in Deferred Rent</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_IncreaseDecreaseInDeferredRent" xml:lang="en-US">Deferred rent</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_IncreaseDecreaseInDeferredRent" xml:lang="en-US">The increase (decrease) during the period in deferred rent.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_IncreaseDecreaseInDeferredRent" xlink:to="lab_atos_IncreaseDecreaseInDeferredRent" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedLiabilities" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_IncreaseDecreaseInAccruedLiabilities" xml:lang="en-US">Increase (Decrease) in Accrued Liabilities, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_IncreaseDecreaseInAccruedLiabilities" xml:lang="en-US">Accrued expenses</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:to="lab_us-gaap_IncreaseDecreaseInAccruedLiabilities" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_LossContingencyAccrualCarryingValuePeriodIncreaseDecrease" xlink:label="loc_us-gaap_LossContingencyAccrualCarryingValuePeriodIncreaseDecrease" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_LossContingencyAccrualCarryingValuePeriodIncreaseDecrease" xml:lang="en-US">Loss Contingency Accrual, Period Increase (Decrease)</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_LossContingencyAccrualCarryingValuePeriodIncreaseDecrease" xml:lang="en-US">Product recall liabilities</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LossContingencyAccrualCarryingValuePeriodIncreaseDecrease" xlink:to="lab_us-gaap_LossContingencyAccrualCarryingValuePeriodIncreaseDecrease" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncreaseDecreaseInOtherCurrentLiabilities" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherCurrentLiabilities" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_IncreaseDecreaseInOtherCurrentLiabilities" xml:lang="en-US">Increase (Decrease) in Other Current Liabilities</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_IncreaseDecreaseInOtherCurrentLiabilities" xml:lang="en-US">Other current liabilities</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInOtherCurrentLiabilities" xlink:to="lab_us-gaap_IncreaseDecreaseInOtherCurrentLiabilities" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" xml:lang="en-US">Net Cash Provided by (Used in) Operating Activities, Continuing Operations, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" xml:lang="en-US">Net cash used in operating activities</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" xlink:to="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xml:lang="en-US">Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xml:lang="en-US">CASH FLOWS FROM INVESTING ACTIVITIES</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:to="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PaymentsToAcquireFurnitureAndFixtures" xlink:label="loc_us-gaap_PaymentsToAcquireFurnitureAndFixtures" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_PaymentsToAcquireFurnitureAndFixtures" xml:lang="en-US">Payments To Acquire Furniture and Fixtures</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="lab_us-gaap_PaymentsToAcquireFurnitureAndFixtures" xml:lang="en-US">Purchase of furniture &amp; fixtures</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsToAcquireFurnitureAndFixtures" xlink:to="lab_us-gaap_PaymentsToAcquireFurnitureAndFixtures" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PaymentsToAcquireSoftware" xlink:label="loc_us-gaap_PaymentsToAcquireSoftware" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_PaymentsToAcquireSoftware" xml:lang="en-US">Payments to Acquire Software</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="lab_us-gaap_PaymentsToAcquireSoftware" xml:lang="en-US">Purchase of software</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsToAcquireSoftware" xlink:to="lab_us-gaap_PaymentsToAcquireSoftware" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xml:lang="en-US">Net Cash Provided by (Used in) Investing Activities, Continuing Operations, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xml:lang="en-US">Net cash used in investing activities</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xlink:to="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract" xml:lang="en-US">Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract" xml:lang="en-US">CASH FLOWS FROM FINANCING ACTIVITIES</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract" xlink:to="lab_us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_ProceedsFromIssuanceOfCommonStockAndWarrants" xlink:label="loc_atos_ProceedsFromIssuanceOfCommonStockAndWarrants" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_ProceedsFromIssuanceOfCommonStockAndWarrants" xml:lang="en-US">Proceeds From Issuance Of Common Stock and Warrants</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_ProceedsFromIssuanceOfCommonStockAndWarrants" xml:lang="en-US">Net proceeds from issuance of common stock and warrants</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_ProceedsFromIssuanceOfCommonStockAndWarrants" xml:lang="en-US">The cash inflow from the issuance of common stock and warrants.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_ProceedsFromIssuanceOfCommonStockAndWarrants" xlink:to="lab_atos_ProceedsFromIssuanceOfCommonStockAndWarrants" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xml:lang="en-US">Net Cash Provided by (Used in) Financing Activities, Continuing Operations, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="lab_us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xml:lang="en-US">Net cash provided by financing activities</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:to="lab_us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:label="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xml:lang="en-US">Cash and Cash Equivalents, Period Increase (Decrease), Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="lab_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xml:lang="en-US">NET INCREASE IN CASH &amp; CASH EQUIVALENTS</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:to="lab_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SupplementalCashFlowElementsAbstract" xlink:label="loc_us-gaap_SupplementalCashFlowElementsAbstract" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SupplementalCashFlowElementsAbstract" xml:lang="en-US">Supplemental Cash Flow Elements [Abstract]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_SupplementalCashFlowElementsAbstract" xml:lang="en-US">SUPPLEMENTAL DISCLOSURES:</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SupplementalCashFlowElementsAbstract" xlink:to="lab_us-gaap_SupplementalCashFlowElementsAbstract" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_InterestPaid" xlink:label="loc_us-gaap_InterestPaid" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_InterestPaid" xml:lang="en-US">Interest Paid, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_InterestPaid" xml:lang="en-US">Interest paid</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InterestPaid" xlink:to="lab_us-gaap_InterestPaid" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:label="loc_us-gaap_NoncashInvestingAndFinancingItemsAbstract" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_NoncashInvestingAndFinancingItemsAbstract" xml:lang="en-US">Noncash Investing and Financing Items [Abstract]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_NoncashInvestingAndFinancingItemsAbstract" xml:lang="en-US">NONCASH INVESTING AND FINANCING ACTIVITIES:</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:to="lab_us-gaap_NoncashInvestingAndFinancingItemsAbstract" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_NonCashReclassificationOfFurnitureAndEquipmentToPrepaidExpenses" xlink:label="loc_atos_NonCashReclassificationOfFurnitureAndEquipmentToPrepaidExpenses" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_NonCashReclassificationOfFurnitureAndEquipmentToPrepaidExpenses" xml:lang="en-US">Non cash Reclassification Of Furniture And Equipment To Prepaid Expenses</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_NonCashReclassificationOfFurnitureAndEquipmentToPrepaidExpenses" xml:lang="en-US">Reclassification of furniture and equipment to prepaid expenses</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_NonCashReclassificationOfFurnitureAndEquipmentToPrepaidExpenses" xml:lang="en-US">Amount of furniture and equipment that has been prepaid under noncash investing activities.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_NonCashReclassificationOfFurnitureAndEquipmentToPrepaidExpenses" xlink:to="lab_atos_NonCashReclassificationOfFurnitureAndEquipmentToPrepaidExpenses" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_CommonStockIssuedForCommitmentFeeInStockPurchaseAgreement" xlink:label="loc_atos_CommonStockIssuedForCommitmentFeeInStockPurchaseAgreement" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_CommonStockIssuedForCommitmentFeeInStockPurchaseAgreement" xml:lang="en-US">Common Stock Issued For Commitment Fee In Stock Purchase Agreement</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_atos_CommonStockIssuedForCommitmentFeeInStockPurchaseAgreement" xml:lang="en-US">Common stock issued as commitment fee under stock purchase agreement</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_CommonStockIssuedForCommitmentFeeInStockPurchaseAgreement" xml:lang="en-US">Common stock issued for commitment fee in stock purchase agreement under noncash investing or financing activities.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_CommonStockIssuedForCommitmentFeeInStockPurchaseAgreement" xlink:to="lab_atos_CommonStockIssuedForCommitmentFeeInStockPurchaseAgreement" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_NatureOfOperations" xlink:label="loc_us-gaap_NatureOfOperations" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_NatureOfOperations" xml:lang="en-US">Nature Of Operations [Text Block]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_NatureOfOperations" xml:lang="en-US">Nature of Operations [Text Block]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NatureOfOperations" xlink:to="lab_us-gaap_NatureOfOperations" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_GoingConcernDisclosureAbstract" xlink:label="loc_atos_GoingConcernDisclosureAbstract" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_GoingConcernDisclosureAbstract" xml:lang="en-US">Going Concern Disclosure [Abstract]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_GoingConcernDisclosureAbstract" xlink:to="lab_atos_GoingConcernDisclosureAbstract" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_GoingConcernDisclosureTextBlock" xlink:label="loc_atos_GoingConcernDisclosureTextBlock" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_GoingConcernDisclosureTextBlock" xml:lang="en-US">Going Concern Disclosure [Text Block]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_GoingConcernDisclosureTextBlock" xml:lang="en-US">Going Concern Disclosure [Text Block]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_GoingConcernDisclosureTextBlock" xml:lang="en-US">The entire disclosure for going concern.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_GoingConcernDisclosureTextBlock" xlink:to="lab_atos_GoingConcernDisclosureTextBlock" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SignificantAccountingPoliciesTextBlock" xlink:label="loc_us-gaap_SignificantAccountingPoliciesTextBlock" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SignificantAccountingPoliciesTextBlock" xml:lang="en-US">Significant Accounting Policies [Text Block]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_SignificantAccountingPoliciesTextBlock" xml:lang="en-US">Significant Accounting Policies [Text Block]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SignificantAccountingPoliciesTextBlock" xlink:to="lab_us-gaap_SignificantAccountingPoliciesTextBlock" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_DocumentAndEntityInformationAbstract" xlink:label="loc_atos_DocumentAndEntityInformationAbstract" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_DocumentAndEntityInformationAbstract" xml:lang="en-US">Document And Entity Information [Abstract]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_DocumentAndEntityInformationAbstract" xlink:to="lab_atos_DocumentAndEntityInformationAbstract" />

    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentInformationTable" xlink:label="loc_dei_DocumentInformationTable" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_dei_DocumentInformationTable" xml:lang="en-US">Document Information [Table]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentInformationTable" xlink:to="lab_dei_DocumentInformationTable" />

    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityRegistrantName" xlink:label="loc_dei_EntityRegistrantName" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_dei_EntityRegistrantName" xml:lang="en-US">Entity Registrant Name</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityRegistrantName" xlink:to="lab_dei_EntityRegistrantName" />

    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityCentralIndexKey" xlink:label="loc_dei_EntityCentralIndexKey" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_dei_EntityCentralIndexKey" xml:lang="en-US">Entity Central Index Key</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityCentralIndexKey" xlink:to="lab_dei_EntityCentralIndexKey" />

    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_CurrentFiscalYearEndDate" xlink:label="loc_dei_CurrentFiscalYearEndDate" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_dei_CurrentFiscalYearEndDate" xml:lang="en-US">Current Fiscal Year End Date</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_CurrentFiscalYearEndDate" xlink:to="lab_dei_CurrentFiscalYearEndDate" />

    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityFilerCategory" xlink:label="loc_dei_EntityFilerCategory" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_dei_EntityFilerCategory" xml:lang="en-US">Entity Filer Category</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityFilerCategory" xlink:to="lab_dei_EntityFilerCategory" />

    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_TradingSymbol" xlink:label="loc_dei_TradingSymbol" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_dei_TradingSymbol" xml:lang="en-US">Trading Symbol</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_TradingSymbol" xlink:to="lab_dei_TradingSymbol" />

    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="loc_dei_EntityCommonStockSharesOutstanding" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_dei_EntityCommonStockSharesOutstanding" xml:lang="en-US">Entity Common Stock, Shares Outstanding</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityCommonStockSharesOutstanding" xlink:to="lab_dei_EntityCommonStockSharesOutstanding" />

    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentType" xlink:label="loc_dei_DocumentType" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_dei_DocumentType" xml:lang="en-US">Document Type</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentType" xlink:to="lab_dei_DocumentType" />

    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_AmendmentFlag" xlink:label="loc_dei_AmendmentFlag" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_dei_AmendmentFlag" xml:lang="en-US">Amendment Flag</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_AmendmentFlag" xlink:to="lab_dei_AmendmentFlag" />

    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentPeriodEndDate" xlink:label="loc_dei_DocumentPeriodEndDate" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_dei_DocumentPeriodEndDate" xml:lang="en-US">Document Period End Date</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentPeriodEndDate" xlink:to="lab_dei_DocumentPeriodEndDate" />

    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="loc_dei_DocumentFiscalPeriodFocus" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_dei_DocumentFiscalPeriodFocus" xml:lang="en-US">Document Fiscal Period Focus</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentFiscalPeriodFocus" xlink:to="lab_dei_DocumentFiscalPeriodFocus" />

    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentFiscalYearFocus" xlink:label="loc_dei_DocumentFiscalYearFocus" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_dei_DocumentFiscalYearFocus" xml:lang="en-US">Document Fiscal Year Focus</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentFiscalYearFocus" xlink:to="lab_dei_DocumentFiscalYearFocus" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="loc_us-gaap_AssetsCurrent" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_AssetsCurrent" xml:lang="en-US">Assets, Current, Total</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="lab_us-gaap_AssetsCurrent" xml:lang="en-US">Total current assets</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetsCurrent" xlink:to="lab_us-gaap_AssetsCurrent" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_OtherAssetsNoncurrentAbstract" xlink:label="loc_us-gaap_OtherAssetsNoncurrentAbstract" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_OtherAssetsNoncurrentAbstract" xml:lang="en-US">Other Assets, Noncurrent [Abstract]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_OtherAssetsNoncurrentAbstract" xml:lang="en-US">Other assets</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherAssetsNoncurrentAbstract" xlink:to="lab_us-gaap_OtherAssetsNoncurrentAbstract" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="loc_us-gaap_EarningsPerShareAbstract" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_EarningsPerShareAbstract" xml:lang="en-US">Earnings Per Share [Abstract]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EarningsPerShareAbstract" xlink:to="lab_us-gaap_EarningsPerShareAbstract" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EarningsPerShareTextBlock" xlink:label="loc_us-gaap_EarningsPerShareTextBlock" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_EarningsPerShareTextBlock" xml:lang="en-US">Earnings Per Share [Text Block]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EarningsPerShareTextBlock" xlink:to="lab_us-gaap_EarningsPerShareTextBlock" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" xml:lang="en-US">Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" xlink:to="lab_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xml:lang="en-US">Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:to="lab_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xml:lang="en-US">Antidilutive Securities [Axis]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:to="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AntidilutiveSecuritiesNameDomain" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_AntidilutiveSecuritiesNameDomain" xml:lang="en-US">Antidilutive Securities, Name [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="lab_us-gaap_AntidilutiveSecuritiesNameDomain" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockOptionMember" xlink:label="loc_us-gaap_StockOptionMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_StockOptionMember" xml:lang="en-US">Equity Option [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockOptionMember" xlink:to="lab_us-gaap_StockOptionMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xml:lang="en-US">Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:to="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xml:lang="en-US">Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:to="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ScheduleOfStockholdersEquityNoteWarrantsOrRightsTextBlock" xlink:label="loc_us-gaap_ScheduleOfStockholdersEquityNoteWarrantsOrRightsTextBlock" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ScheduleOfStockholdersEquityNoteWarrantsOrRightsTextBlock" xml:lang="en-US">Schedule of Stockholders&#39; Equity Note, Warrants or Rights [Table Text Block]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfStockholdersEquityNoteWarrantsOrRightsTextBlock" xlink:to="lab_us-gaap_ScheduleOfStockholdersEquityNoteWarrantsOrRightsTextBlock" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfWarrantOrRightTable" xlink:label="loc_us-gaap_ClassOfWarrantOrRightTable" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ClassOfWarrantOrRightTable" xml:lang="en-US">Class of Warrant or Right [Table]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ClassOfWarrantOrRightTable" xlink:to="lab_us-gaap_ClassOfWarrantOrRightTable" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_PlacementAgentFeeMember" xlink:label="loc_atos_PlacementAgentFeeMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_PlacementAgentFeeMember" xml:lang="en-US">Placement Agent Fee [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_PlacementAgentFeeMember" xlink:to="lab_atos_PlacementAgentFeeMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfWarrantOrRightLineItems" xlink:label="loc_us-gaap_ClassOfWarrantOrRightLineItems" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ClassOfWarrantOrRightLineItems" xml:lang="en-US">Class of Warrant or Right [Line Items]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ClassOfWarrantOrRightLineItems" xlink:to="lab_us-gaap_ClassOfWarrantOrRightLineItems" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfWarrantOrRightOutstanding" xlink:label="loc_us-gaap_ClassOfWarrantOrRightOutstanding" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ClassOfWarrantOrRightOutstanding" xml:lang="en-US">Class of Warrant or Right, Outstanding</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ClassOfWarrantOrRightOutstanding" xlink:to="lab_us-gaap_ClassOfWarrantOrRightOutstanding" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:label="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xml:lang="en-US">Class of Warrant or Right, Exercise Price of Warrants or Rights</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:to="lab_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfWarrantOrRighstDateFromWhichWarrantsOrRightsExercisable" xlink:label="loc_us-gaap_ClassOfWarrantOrRighstDateFromWhichWarrantsOrRightsExercisable" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ClassOfWarrantOrRighstDateFromWhichWarrantsOrRightsExercisable" xml:lang="en-US">Class of Warrant or Right, Date from which Warrants or Rights Exercisable</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ClassOfWarrantOrRighstDateFromWhichWarrantsOrRightsExercisable" xlink:to="lab_us-gaap_ClassOfWarrantOrRighstDateFromWhichWarrantsOrRightsExercisable" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_StockholdersEquityLineItems" xlink:label="loc_atos_StockholdersEquityLineItems" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_StockholdersEquityLineItems" xml:lang="en-US">Stockholder&#39;s Equity [Line Items]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_StockholdersEquityLineItems" xlink:to="lab_atos_StockholdersEquityLineItems" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ClassOfStockDomain" xml:lang="en-US">Class of Stock [Domain]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ClassOfStockDomain" xlink:to="lab_us-gaap_ClassOfStockDomain" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SeriesAPreferredStockMember" xlink:label="loc_us-gaap_SeriesAPreferredStockMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SeriesAPreferredStockMember" xml:lang="en-US">Series A Preferred Stock [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SeriesAPreferredStockMember" xlink:to="lab_us-gaap_SeriesAPreferredStockMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentInformationLineItems" xlink:label="loc_dei_DocumentInformationLineItems" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_dei_DocumentInformationLineItems" xml:lang="en-US">Document Information [Line Items]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentInformationLineItems" xlink:to="lab_dei_DocumentInformationLineItems" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_ExecutivesAndOfficersMember" xlink:label="loc_atos_ExecutivesAndOfficersMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_ExecutivesAndOfficersMember" xml:lang="en-US">Executives and Officers [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_ExecutivesAndOfficersMember" xlink:to="lab_atos_ExecutivesAndOfficersMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_DirectorsCompensationPaid" xlink:label="loc_atos_DirectorsCompensationPaid" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_DirectorsCompensationPaid" xml:lang="en-US">Directors Compensation Paid</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_DirectorsCompensationPaid" xml:lang="en-US">The amount of cash paid during the period in connection with a new compensation plan adopted by the Board of Directors for independent members.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_DirectorsCompensationPaid" xlink:to="lab_atos_DirectorsCompensationPaid" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_SeniorOfficersMember" xlink:label="loc_atos_SeniorOfficersMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_SeniorOfficersMember" xml:lang="en-US">Senior Officers [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_SeniorOfficersMember" xlink:to="lab_atos_SeniorOfficersMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_PercentageOfSharesSoldInOffering" xlink:label="loc_atos_PercentageOfSharesSoldInOffering" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_PercentageOfSharesSoldInOffering" xml:lang="en-US">Percentage of Shares Sold in Offering</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_PercentageOfSharesSoldInOffering" xml:lang="en-US">This item refers to percentage of aggregate number of shares sold in the offering.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_PercentageOfSharesSoldInOffering" xlink:to="lab_atos_PercentageOfSharesSoldInOffering" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SubsequentEventLineItems" xlink:label="loc_us-gaap_SubsequentEventLineItems" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SubsequentEventLineItems" xml:lang="en-US">Subsequent Event [Line Items]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubsequentEventLineItems" xlink:to="lab_us-gaap_SubsequentEventLineItems" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_BeneficialOwnerMember" xlink:label="loc_us-gaap_BeneficialOwnerMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_BeneficialOwnerMember" xml:lang="en-US">Beneficial Owner [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BeneficialOwnerMember" xlink:to="lab_us-gaap_BeneficialOwnerMember" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_PercentageOfCommonStockOutstanding" xlink:label="loc_atos_PercentageOfCommonStockOutstanding" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_PercentageOfCommonStockOutstanding" xml:lang="en-US">Percentage of Common Stock Outstanding</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_PercentageOfCommonStockOutstanding" xml:lang="en-US">This item refers to percentage of common stock outstanding.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_PercentageOfCommonStockOutstanding" xlink:to="lab_atos_PercentageOfCommonStockOutstanding" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_EntitledToReceiveWorthOfCommonStock" xlink:label="loc_atos_EntitledToReceiveWorthOfCommonStock" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_EntitledToReceiveWorthOfCommonStock" xml:lang="en-US">Entitled to Receive Worth of Common Stock</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_EntitledToReceiveWorthOfCommonStock" xml:lang="en-US">Entitled to receive a worth of the Company&#8217;s common stock.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_EntitledToReceiveWorthOfCommonStock" xlink:to="lab_atos_EntitledToReceiveWorthOfCommonStock" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xml:lang="en-US">Aggregate Intrinsic Value, Exercised (in dollars)</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRights" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRights" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRights" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRights" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRights" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SharesHeldInEmployeeStockOptionPlanSuspenseShares" xlink:label="loc_us-gaap_SharesHeldInEmployeeStockOptionPlanSuspenseShares" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SharesHeldInEmployeeStockOptionPlanSuspenseShares" xml:lang="en-US">Shares held in Employee Stock Option Plan, Suspense Shares</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SharesHeldInEmployeeStockOptionPlanSuspenseShares" xlink:to="lab_us-gaap_SharesHeldInEmployeeStockOptionPlanSuspenseShares" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xml:lang="en-US">Aggregate Intrinsic Value, Exercisable as of June 30, 2014</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xlink:to="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Aggregate Intrinsic Value</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue" xml:lang="en-US">Aggregate Intrinsic Value, Vested and expected to vest (1)</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StatementOfStockholdersEquityAbstract" xlink:label="loc_us-gaap_StatementOfStockholdersEquityAbstract" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_StatementOfStockholdersEquityAbstract" xml:lang="en-US">Statement of Stockholders&#39; Equity [Abstract]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementOfStockholdersEquityAbstract" xlink:to="lab_us-gaap_StatementOfStockholdersEquityAbstract" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_CommonStockMember" xlink:label="loc_us-gaap_CommonStockMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_CommonStockMember" xml:lang="en-US">Common Stock [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommonStockMember" xlink:to="lab_us-gaap_CommonStockMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_AdditionalPaidInCapitalMember" xml:lang="en-US">Additional Paid-in Capital [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AdditionalPaidInCapitalMember" xlink:to="lab_us-gaap_AdditionalPaidInCapitalMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AccumulatedDeficitDuringDevelopmentStageMember" xlink:label="loc_us-gaap_AccumulatedDeficitDuringDevelopmentStageMember" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_AccumulatedDeficitDuringDevelopmentStageMember" xml:lang="en-US">Accumulated Deficit during Development Stage [Member]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccumulatedDeficitDuringDevelopmentStageMember" xlink:to="lab_us-gaap_AccumulatedDeficitDuringDevelopmentStageMember" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SharesOutstanding" xlink:label="loc_us-gaap_SharesOutstanding" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SharesOutstanding" xml:lang="en-US">Shares, Outstanding</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="lab_us-gaap_SharesOutstanding" xml:lang="en-US">Balance (in shares)</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="lab_us-gaap_SharesOutstanding" xml:lang="en-US">Balance (in shares)</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SharesOutstanding" xlink:to="lab_us-gaap_SharesOutstanding" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueIssuedForCash" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueIssuedForCash" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_StockIssuedDuringPeriodValueIssuedForCash" xml:lang="en-US">Development Stage Entities, Stock Issued, Value, Issued for Cash</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_StockIssuedDuringPeriodValueIssuedForCash" xml:lang="en-US">Issuance of common shares for cash</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockIssuedDuringPeriodValueIssuedForCash" xlink:to="lab_us-gaap_StockIssuedDuringPeriodValueIssuedForCash" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesIssuedForCash" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesIssuedForCash" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesIssuedForCash" xml:lang="en-US">Development Stage Entities, Stock Issued, Shares, Issued for Cash</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesIssuedForCash" xml:lang="en-US">Issuance of common shares for cash (in shares)</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockIssuedDuringPeriodSharesIssuedForCash" xlink:to="lab_us-gaap_StockIssuedDuringPeriodSharesIssuedForCash" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesIssuedForServices" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesIssuedForServices" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesIssuedForServices" xml:lang="en-US">Stock Issued During Period, Shares, Issued for Services</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesIssuedForServices" xml:lang="en-US">Issuance of common shares for services (in shares)</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockIssuedDuringPeriodSharesIssuedForServices" xlink:to="lab_us-gaap_StockIssuedDuringPeriodSharesIssuedForServices" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_FinancingFeeFromPublicOfferig" xlink:label="loc_atos_FinancingFeeFromPublicOfferig" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_FinancingFeeFromPublicOfferig" xml:lang="en-US">Financing fee from public offerig</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_FinancingFeeFromPublicOfferig" xml:lang="en-US">Financing fees from 2014 Public Offering</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_FinancingFeeFromPublicOfferig" xml:lang="en-US">The amount of financing fee generated from public offering during the period</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_FinancingFeeFromPublicOfferig" xlink:to="lab_atos_FinancingFeeFromPublicOfferig" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts" xml:lang="en-US">Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="lab_us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts" xml:lang="en-US">Amortization of deferred financing costs</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts" xlink:to="lab_us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_StockIssuedDuringPeriodValueWarrantsExercised" xlink:label="loc_atos_StockIssuedDuringPeriodValueWarrantsExercised" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_StockIssuedDuringPeriodValueWarrantsExercised" xml:lang="en-US">Stock Issued During Period Value Warrants Exercised</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_StockIssuedDuringPeriodValueWarrantsExercised" xml:lang="en-US">Issuance of Common shares upon exercise of warrants</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_StockIssuedDuringPeriodValueWarrantsExercised" xml:lang="en-US">Value of shares issued for warrants exercised during the period.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_StockIssuedDuringPeriodValueWarrantsExercised" xlink:to="lab_atos_StockIssuedDuringPeriodValueWarrantsExercised" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_StockIssuedDuringPeriodSharesWarrantsExercise" xlink:label="loc_atos_StockIssuedDuringPeriodSharesWarrantsExercise" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_StockIssuedDuringPeriodSharesWarrantsExercise" xml:lang="en-US">Stock Issued During Period Shares Warrants Exercise</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_StockIssuedDuringPeriodSharesWarrantsExercise" xml:lang="en-US">Issuance of Common shares upon exercise of warrants (in shares)</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_StockIssuedDuringPeriodSharesWarrantsExercise" xml:lang="en-US">Number of shares issued upon warrants exercised during the period.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_StockIssuedDuringPeriodSharesWarrantsExercise" xlink:to="lab_atos_StockIssuedDuringPeriodSharesWarrantsExercise" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueEmployeeStockOwnershipPlan" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueEmployeeStockOwnershipPlan" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_StockIssuedDuringPeriodValueEmployeeStockOwnershipPlan" xml:lang="en-US">Stock Issued During Period, Value, Employee Stock Ownership Plan</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_StockIssuedDuringPeriodValueEmployeeStockOwnershipPlan" xml:lang="en-US">Employees option exercise and cancellation of restricted stock grants</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockIssuedDuringPeriodValueEmployeeStockOwnershipPlan" xlink:to="lab_us-gaap_StockIssuedDuringPeriodValueEmployeeStockOwnershipPlan" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesEmployeeStockOwnershipPlan" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockOwnershipPlan" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockOwnershipPlan" xml:lang="en-US">Stock Issued During Period, Shares, Employee Stock Ownership Plan</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockOwnershipPlan" xml:lang="en-US">Employees option exercise and cancellation of restricted stock grants (in shares)</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockOwnershipPlan" xlink:to="lab_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockOwnershipPlan" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_PriorPeriodReclassificationAdjustmentDescription" xlink:label="loc_us-gaap_PriorPeriodReclassificationAdjustmentDescription" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_PriorPeriodReclassificationAdjustmentDescription" xml:lang="en-US">Reclassification, Policy [Policy Text Block]</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PriorPeriodReclassificationAdjustmentDescription" xlink:to="lab_us-gaap_PriorPeriodReclassificationAdjustmentDescription" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesAcquisitions" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesAcquisitions" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesAcquisitions" xml:lang="en-US">Stock Issued During Period, Shares, Acquisitions</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesAcquisitions" xml:lang="en-US">Stock Issued During Period, Shares, Acquisitions</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockIssuedDuringPeriodSharesAcquisitions" xlink:to="lab_us-gaap_StockIssuedDuringPeriodSharesAcquisitions" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_WarrantsIssuedDuringPeriodAcquisitions" xlink:label="loc_atos_WarrantsIssuedDuringPeriodAcquisitions" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_WarrantsIssuedDuringPeriodAcquisitions" xml:lang="en-US">Warrants Issued During Period Acquisitions</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_WarrantsIssuedDuringPeriodAcquisitions" xml:lang="en-US">Number of shares of warrants issued during the period pursuant to acquisitions.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_WarrantsIssuedDuringPeriodAcquisitions" xlink:to="lab_atos_WarrantsIssuedDuringPeriodAcquisitions" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_WarrantPrice" xlink:label="loc_atos_WarrantPrice" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_WarrantPrice" xml:lang="en-US">Warrant Price</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_WarrantPrice" xml:lang="en-US">The price per warrants valued using Black-Scholes-Merton Valuation Technique to determine fair value of the warrants.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_WarrantPrice" xlink:to="lab_atos_WarrantPrice" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:label="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xml:lang="en-US">Increase (Decrease) in Operating Capital [Abstract]</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xml:lang="en-US">Changes in operating assets and liabilities:</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="lab_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xml:lang="en-US">Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xml:lang="en-US">Compensation cost for stock options granted to executives and employees</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:to="lab_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xml:lang="en-US">Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:to="lab_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" />

    <loc xlink:type="locator" xlink:href="atos-20140630.xsd#atos_MonthlyLeaseRent" xlink:label="loc_atos_MonthlyLeaseRent" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_atos_MonthlyLeaseRent" xml:lang="en-US">Monthly Lease Rent</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="lab_atos_MonthlyLeaseRent" xml:lang="en-US">Monthly Lease Rent</label>

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="lab_atos_MonthlyLeaseRent" xml:lang="en-US">Amount of monthly lease rent paid by the entity during the period.</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_atos_MonthlyLeaseRent" xlink:to="lab_atos_MonthlyLeaseRent" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_EquityMethodInvestmentOwnershipPercentage" xml:lang="en-US">Equity Method Investment, Ownership Percentage</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:to="lab_us-gaap_EquityMethodInvestmentOwnershipPercentage" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares" xlink:to="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares" />

    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2014/elts/us-gaap-2014-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" />

    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xml:lang="en-US">Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized</label>

    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:to="lab_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" />
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