veracyte is now contracted as an in-network service provider to health plans representing over 200 million people in the united states our second commercial product , the percepta classifier , is the first genomic test to gain medicare coverage for improved lung cancer screening and diagnosis , making it a covered benefit for more than 60 million people . 50 fourth quarter and full-year 2018 financial results for the three- and twelve-month periods ended december 31 , 2018 , compared to the prior year : revenue was $ 25.8 million and $ 92.0 million , respectively , an increase of 31 % and 28 % ; gross margin was 66 % and 64 % , respectively , an increase of 6 % and 3 % ; operating expenses , excluding cost of revenue , were $ 20.1 million and $ 81.2 million , respectively , an increase of 12 % and 15 % ; net loss and comprehensive loss was ( $ 3.1 ) million and ( $ 23.0 ) million , respectively , an improvement of 63 % and 26 % ; basic and diluted net loss per common share was ( $ 0.08 ) and ( $ 0.62 ) , respectively , an improvement , of 67 % and 32 % ; net cash used in operating activities was $ 1.2 million and $ 13.5 million , respectively , an improvement of 79 % and 44 % ; cash burn ( 1 ) was $ 1.7 million and $ 15.4 million , respectively , an improvement of 73 % and 39 % ; and cash and cash equivalents was $ 78.0 million at december 31 , 2018 . ( 1 ) a reconciliation of net cash used in operating activities to cash burn has been provided below : to supplement our financial statements prepared in accordance with u. s. gaap , we monitor and consider cash burn , which is a non-u.s. gaap financial measure . this non-u.s. gaap financial measure is not based on any standardized methodology prescribed by u.s. gaap and is not necessarily comparable to similarly-titled measures presented by other companies . we define cash burn as net cash used in operating activities plus net capital expenditures , such as net purchases of property and equipment . we believe cash burn to be a liquidity measure that provides useful information to management and investors about the amount of cash consumed by the operations of the business , including our purchases of property and equipment . a limitation of using this non-u.s. gaap measure is that cash burn does not represent the total change in cash , cash equivalents and restricted cash for the period because it excludes cash provided by or used for other investing and financing activities . we account for this limitation by providing information about our capital expenditures and other investing and financing activities in the statements of cash flows in our financial statements and by presenting cash flows from investing and financing activities in our reconciliation of cash burn . in addition , it is important to note that other companies , including companies in our industry , may not use cash burn , may calculate cash burn in a different manner than we do or may use other financial measures to evaluate their performance , all of which could reduce the usefulness of cash burn as a comparative measure . because of these limitations , cash burn should not be considered in isolation from , or as a substitute for , financial information prepared in accordance with u.s. gaap . the reconciliation of cash burn to net cash used in operating activities is provided in the table below ( in thousands of dollars ) : replace_table_token_4_th 2018 full-year and recent business highlights commercial expansion : grew total genomic test volume to 9,154 tests in the fourth quarter of 2018 , representing 28 % growth over 2017 , which resulted in full-year 2018 growth of 22 % over 2017 , or 31,710 tests . 51 transitioned all afirma customers to the second-generation afirma genomic sequencing classifier ( gsc ) platform and launched the afirma xpression atlas to provide a comprehensive solution that informs both thyroid cancer diagnosis and treatment decisions . notably , 30 % of afirma gsc orders included xpression atlas in 2018 , ahead of the company 's expectations . grew percepta bronchial genomic classifier volume to nearly 1,550 tests in its first full year of commercialization , with genomic volume accelerating 74 % sequentially from the third quarter to the fourth quarter of 2018. esta blished 20 leading early access program ( eap ) sites across the united states for envisia in 2018 , addressing physician demand for patient access to the classifier which improves idiopathic pulmonary fibrosis ( ipf ) diagnosis and builds a solid foundation for the company to commercially expand it in 2019. biopharmaceutical collaborations executed a long-term strategic collaboration with johnson & johnson , llc and johnson & johnson 's lung cancer initiative to advance diagnostics , including a nasal swab test , for early lung cancer detection . veracyte estimates the combined monetary and non-monetary value of the collaboration to be more than $ 50 million . the company believes this collaboration expands its addressable lung cancer diagnostic market to a more than $ 30 billion global opportunity . entered into a research collaboration with loxo oncology , through which loxo has access to data from veracyte 's afirma xpression atlas platform to help in its development of therapies for patients with genetically defined cancers , including thyroid cancer . reimbursement progress : received draft medicare coverage for the envisia genomic classifier through the moldx program , with a final positive coverage decision expected in early 2019. achieved in-network status as a service provider with the last of the major commercial health plans , which veracyte believes will facilitate coverage and reimbursement for its percepta and envisia classifiers . story_separator_special_tag we have also incurred increased selling and marketing expense as a result of investments in our lung product portfolio and believe total selling and marketing expenses will continue to increase as we launch and promote our new tests . general and administrative general and administrative expenses include compensation expenses for executive officers and administrative , billing and client service personnel , professional fees for legal and audit services , occupancy costs , depreciation and amortization , and other expenses such as information technology and miscellaneous expenses offset by allocation of facility and information technology expenses to other functions . for the year ended december 31 , 2018 , approximately 66 % of the average headcount classified as general and administrative encompass our billing and customer care teams . we expect general and administrative expenses to continue to increase as we build our general and administration infrastructure and to stabilize thereafter . intangible asset amortization intangible asset amortization began in april 2015 when we launched the percepta test . the related finite-lived intangible asset with a cost of $ 16.0 million and a net book value of $ 12.0 million at december 31 , 2018 is being amortized over 15 years , using the straight-line method . interest expense interest expense is attributable to our borrowings under debt agreements and capital leases as well as costs associated with the pre-payment of debt . other income , net other income , net consists primarily of sublease rental income and interest income received from payers and from our cash equivalents . critical accounting policies and estimates our management 's discussion and analysis of our financial condition and results of operations is based on our audited financial statements , which have been prepared in accordance with united states generally accepted accounting principles , or u.s. gaap . the preparation of the financial statements requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements , as well as the reported revenue generated and expenses incurred during the reporting periods . our estimates are based on our historical experience and on various other factors that we believe are reasonable under the circumstances , the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources . actual results may differ from these estimates under different assumptions or conditions and any such differences may be material . we believe that the accounting policies discussed below are critical to understanding our historical and future performance , as these policies relate to the more significant areas involving management 's judgments and estimates . revenue from diagnostic services 56 we recognize revenue related to billings on an accrual basis based on estimates of the amount that will ultimately be realized . in determining the amount to accrue for a delivered test , we consider factors such as payment history , payer coverage , whether there is a reimbursement contract between the payer and us , payment as a percentage of agreed upon rate ( if applicable ) , amount paid per test and any current developments or changes that could impact reimbursement . these estimates require significant judgment by management . generally , we determine accrual rates based on the average reimbursement from payers for tests that are on average a year old , since it can take a significant period of time to collect from some payers . except in situations where we believe the rate we reasonably expect to collect to vary due to a coverage decision , contract , more recent reimbursement data or evidence to the contrary , we use an average of reimbursement for tests provided over four quarters as it reduces the effects of temporary volatility and seasonal effects . we use judgment in determining accrual rates and our judgments will continue to evolve in the future as we continue to gain reimbursement experience . arrangements with multiple-performance obligations from time to time , we enter into arrangements for the research and development and or commercialization of services . such arrangements may require us to deliver various rights , services and or samples , including intellectual property rights/licenses , research and development services , and or commercialization of services . the underlying terms of these arrangements generally provide for consideration to us in the form of nonrefundable upfront license fees , development and commercial performance milestone payments , royalty payments and or profit sharing . in arrangements involving more than one performance obligation , each required performance obligation is evaluated to determine whether it qualifies as a distinct performance obligation based on whether ( i ) the customer can benefit from the good or service either on its own or together with other resources that are readily available and ( ii ) the good or service is separately identifiable from other promises in the contract . the consideration under the arrangement is then allocated to each separate distinct performance obligation based on its respective relative stand-alone selling price . the estimated selling price of each deliverable reflects our best estimate of what the selling price would be if the deliverable was regularly sold by us on a stand-alone basis or using an adjusted market assessment approach if selling price on a stand-alone basis is not available . the consideration allocated to each distinct performance obligation is recognized as revenue when control of the related goods or services is transferred . consideration associated with at-risk substantive performance milestones is recognized as revenue when it is probable that a significant reversal of the cumulative revenue recognized will not occur . should there be royalties , we utilize the sales and usage-based royalty exception in arrangements that resulted from the license of intellectual property , recognizing revenues generated from royalties or profit sharing as the underlying sales occur . other significant accounting

cash flows the following table summarizes our cash flows for the years ended december 31 , 2018 , 2017 and 2016 ( in thousands of dollars ) : 63 replace_table_token_12_th cash flows from operating activities cash used in operating activities for the year ended december 31 , 2018 was $ 13.5 million . the net loss of $ 23.0 million includes non-cash charges of $ 6.0 million of stock-based compensation expense and $ 3.9 million of depreciation and amortization , which includes $ 1.1 million of intangible asset amortization . it also includes $ 0.3 million of end-of-term debt obligation accruals . cash used as a result of changes in operating assets and liabilities of $ 0.7 million was primarily due to a decrease in accounts payable of $ 1.6 million , an increase in other assets of $ 0.8 million and increases in prepaid expenses and other current assets and accounts receivable of $ 0.9 million , partially offset by a decrease in supplies of $ 1.9 million and an increase in accrued liabilities and deferred rent of $ 0.7 million . cash used in operating activities for the year ended december 31 , 2017 was $ 23.9 million . the net loss of $ 31.0 million includes non-cash charges of $ 6.6 million of stock-based compensation expense and $ 3.8 million of depreciation and amortization , which includes $ 1.1 million of intangible asset amortization . it also includes a $ 1.5 million prepayment penalty for exiting our previous credit agreement which is a financing cash flow , and the amortization and write-off of $ 0.5 million of debt issuance costs .


 Write a concise suspicious activity report of the following text delimited by triple backquotes. Return your response as a formal report which covers the key points highlighting the location,dates,entity names and account holder information in chronological order of the text.
     ```cash flows the following table summarizes our cash flows for the years ended december 31 , 2018 , 2017 and 2016 ( in thousands of dollars ) : 63 replace_table_token_12_th cash flows from operating activities cash used in operating activities for the year ended december 31 , 2018 was $ 13.5 million . the net loss of $ 23.0 million includes non-cash charges of $ 6.0 million of stock-based compensation expense and $ 3.9 million of depreciation and amortization , which includes $ 1.1 million of intangible asset amortization . it also includes $ 0.3 million of end-of-term debt obligation accruals . cash used as a result of changes in operating assets and liabilities of $ 0.7 million was primarily due to a decrease in accounts payable of $ 1.6 million , an increase in other assets of $ 0.8 million and increases in prepaid expenses and other current assets and accounts receivable of $ 0.9 million , partially offset by a decrease in supplies of $ 1.9 million and an increase in accrued liabilities and deferred rent of $ 0.7 million . cash used in operating activities for the year ended december 31 , 2017 was $ 23.9 million . the net loss of $ 31.0 million includes non-cash charges of $ 6.6 million of stock-based compensation expense and $ 3.8 million of depreciation and amortization , which includes $ 1.1 million of intangible asset amortization . it also includes a $ 1.5 million prepayment penalty for exiting our previous credit agreement which is a financing cash flow , and the amortization and write-off of $ 0.5 million of debt issuance costs .
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 Suspicious Activity Report : veracyte is now contracted as an in-network service provider to health plans representing over 200 million people in the united states our second commercial product , the percepta classifier , is the first genomic test to gain medicare coverage for improved lung cancer screening and diagnosis , making it a covered benefit for more than 60 million people . 50 fourth quarter and full-year 2018 financial results for the three- and twelve-month periods ended december 31 , 2018 , compared to the prior year : revenue was $ 25.8 million and $ 92.0 million , respectively , an increase of 31 % and 28 % ; gross margin was 66 % and 64 % , respectively , an increase of 6 % and 3 % ; operating expenses , excluding cost of revenue , were $ 20.1 million and $ 81.2 million , respectively , an increase of 12 % and 15 % ; net loss and comprehensive loss was ( $ 3.1 ) million and ( $ 23.0 ) million , respectively , an improvement of 63 % and 26 % ; basic and diluted net loss per common share was ( $ 0.08 ) and ( $ 0.62 ) , respectively , an improvement , of 67 % and 32 % ; net cash used in operating activities was $ 1.2 million and $ 13.5 million , respectively , an improvement of 79 % and 44 % ; cash burn ( 1 ) was $ 1.7 million and $ 15.4 million , respectively , an improvement of 73 % and 39 % ; and cash and cash equivalents was $ 78.0 million at december 31 , 2018 . ( 1 ) a reconciliation of net cash used in operating activities to cash burn has been provided below : to supplement our financial statements prepared in accordance with u. s. gaap , we monitor and consider cash burn , which is a non-u.s. gaap financial measure . this non-u.s. gaap financial measure is not based on any standardized methodology prescribed by u.s. gaap and is not necessarily comparable to similarly-titled measures presented by other companies . we define cash burn as net cash used in operating activities plus net capital expenditures , such as net purchases of property and equipment . we believe cash burn to be a liquidity measure that provides useful information to management and investors about the amount of cash consumed by the operations of the business , including our purchases of property and equipment . a limitation of using this non-u.s. gaap measure is that cash burn does not represent the total change in cash , cash equivalents and restricted cash for the period because it excludes cash provided by or used for other investing and financing activities . we account for this limitation by providing information about our capital expenditures and other investing and financing activities in the statements of cash flows in our financial statements and by presenting cash flows from investing and financing activities in our reconciliation of cash burn . in addition , it is important to note that other companies , including companies in our industry , may not use cash burn , may calculate cash burn in a different manner than we do or may use other financial measures to evaluate their performance , all of which could reduce the usefulness of cash burn as a comparative measure . because of these limitations , cash burn should not be considered in isolation from , or as a substitute for , financial information prepared in accordance with u.s. gaap . the reconciliation of cash burn to net cash used in operating activities is provided in the table below ( in thousands of dollars ) : replace_table_token_4_th 2018 full-year and recent business highlights commercial expansion : grew total genomic test volume to 9,154 tests in the fourth quarter of 2018 , representing 28 % growth over 2017 , which resulted in full-year 2018 growth of 22 % over 2017 , or 31,710 tests . 51 transitioned all afirma customers to the second-generation afirma genomic sequencing classifier ( gsc ) platform and launched the afirma xpression atlas to provide a comprehensive solution that informs both thyroid cancer diagnosis and treatment decisions . notably , 30 % of afirma gsc orders included xpression atlas in 2018 , ahead of the company 's expectations . grew percepta bronchial genomic classifier volume to nearly 1,550 tests in its first full year of commercialization , with genomic volume accelerating 74 % sequentially from the third quarter to the fourth quarter of 2018. esta blished 20 leading early access program ( eap ) sites across the united states for envisia in 2018 , addressing physician demand for patient access to the classifier which improves idiopathic pulmonary fibrosis ( ipf ) diagnosis and builds a solid foundation for the company to commercially expand it in 2019. biopharmaceutical collaborations executed a long-term strategic collaboration with johnson & johnson , llc and johnson & johnson 's lung cancer initiative to advance diagnostics , including a nasal swab test , for early lung cancer detection . veracyte estimates the combined monetary and non-monetary value of the collaboration to be more than $ 50 million . the company believes this collaboration expands its addressable lung cancer diagnostic market to a more than $ 30 billion global opportunity . entered into a research collaboration with loxo oncology , through which loxo has access to data from veracyte 's afirma xpression atlas platform to help in its development of therapies for patients with genetically defined cancers , including thyroid cancer . reimbursement progress : received draft medicare coverage for the envisia genomic classifier through the moldx program , with a final positive coverage decision expected in early 2019. achieved in-network status as a service provider with the last of the major commercial health plans , which veracyte believes will facilitate coverage and reimbursement for its percepta and envisia classifiers . story_separator_special_tag we have also incurred increased selling and marketing expense as a result of investments in our lung product portfolio and believe total selling and marketing expenses will continue to increase as we launch and promote our new tests . general and administrative general and administrative expenses include compensation expenses for executive officers and administrative , billing and client service personnel , professional fees for legal and audit services , occupancy costs , depreciation and amortization , and other expenses such as information technology and miscellaneous expenses offset by allocation of facility and information technology expenses to other functions . for the year ended december 31 , 2018 , approximately 66 % of the average headcount classified as general and administrative encompass our billing and customer care teams . we expect general and administrative expenses to continue to increase as we build our general and administration infrastructure and to stabilize thereafter . intangible asset amortization intangible asset amortization began in april 2015 when we launched the percepta test . the related finite-lived intangible asset with a cost of $ 16.0 million and a net book value of $ 12.0 million at december 31 , 2018 is being amortized over 15 years , using the straight-line method . interest expense interest expense is attributable to our borrowings under debt agreements and capital leases as well as costs associated with the pre-payment of debt . other income , net other income , net consists primarily of sublease rental income and interest income received from payers and from our cash equivalents . critical accounting policies and estimates our management 's discussion and analysis of our financial condition and results of operations is based on our audited financial statements , which have been prepared in accordance with united states generally accepted accounting principles , or u.s. gaap . the preparation of the financial statements requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements , as well as the reported revenue generated and expenses incurred during the reporting periods . our estimates are based on our historical experience and on various other factors that we believe are reasonable under the circumstances , the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources . actual results may differ from these estimates under different assumptions or conditions and any such differences may be material . we believe that the accounting policies discussed below are critical to understanding our historical and future performance , as these policies relate to the more significant areas involving management 's judgments and estimates . revenue from diagnostic services 56 we recognize revenue related to billings on an accrual basis based on estimates of the amount that will ultimately be realized . in determining the amount to accrue for a delivered test , we consider factors such as payment history , payer coverage , whether there is a reimbursement contract between the payer and us , payment as a percentage of agreed upon rate ( if applicable ) , amount paid per test and any current developments or changes that could impact reimbursement . these estimates require significant judgment by management . generally , we determine accrual rates based on the average reimbursement from payers for tests that are on average a year old , since it can take a significant period of time to collect from some payers . except in situations where we believe the rate we reasonably expect to collect to vary due to a coverage decision , contract , more recent reimbursement data or evidence to the contrary , we use an average of reimbursement for tests provided over four quarters as it reduces the effects of temporary volatility and seasonal effects . we use judgment in determining accrual rates and our judgments will continue to evolve in the future as we continue to gain reimbursement experience . arrangements with multiple-performance obligations from time to time , we enter into arrangements for the research and development and or commercialization of services . such arrangements may require us to deliver various rights , services and or samples , including intellectual property rights/licenses , research and development services , and or commercialization of services . the underlying terms of these arrangements generally provide for consideration to us in the form of nonrefundable upfront license fees , development and commercial performance milestone payments , royalty payments and or profit sharing . in arrangements involving more than one performance obligation , each required performance obligation is evaluated to determine whether it qualifies as a distinct performance obligation based on whether ( i ) the customer can benefit from the good or service either on its own or together with other resources that are readily available and ( ii ) the good or service is separately identifiable from other promises in the contract . the consideration under the arrangement is then allocated to each separate distinct performance obligation based on its respective relative stand-alone selling price . the estimated selling price of each deliverable reflects our best estimate of what the selling price would be if the deliverable was regularly sold by us on a stand-alone basis or using an adjusted market assessment approach if selling price on a stand-alone basis is not available . the consideration allocated to each distinct performance obligation is recognized as revenue when control of the related goods or services is transferred . consideration associated with at-risk substantive performance milestones is recognized as revenue when it is probable that a significant reversal of the cumulative revenue recognized will not occur . should there be royalties , we utilize the sales and usage-based royalty exception in arrangements that resulted from the license of intellectual property , recognizing revenues generated from royalties or profit sharing as the underlying sales occur . other significant accounting

