we are also entitled to sublicensing revenues in those situations where our collaborators choose to license our technologies to other parties . as we continue to shift our focus on our healthcare business , we have and may continue to mutually terminate collaboration agreements or repurchase rights to the exclusive fields from collaborators , relieving us of any further performance obligations under the agreement . upon such circumstances or when we determine no further performance obligations are required of us under an agreement , we may recognize any remaining deferred revenue as either collaboration revenue or as a reduction of operating expense , depending on the circumstances . see `` notes to the consolidated financial statements - note 6 `` appearing elsewhere in this annual report for a discussion of changes to our significant collaborations . we generate product and service revenues primarily through sales of products or services that are created from technologies developed or owned by us . our primary current offerings arise from trans ova and include sales of advanced reproductive technologies , including our bovine embryo transfer and ivf processes and from genetic preservation and sexed semen processes , and applications of such processes to other livestock , as well as sales of livestock and embryos produced using these processes and used in production . exemplar also generates product and service revenues through the development and sale of genetically engineered miniature swine models . we recognize revenue when control of the promised product is transferred to the customer or when the promised service is completed . in future periods , in connection with our focus on healthcare , our revenues will primarily depend on our ability to advance and create our own programs and the extent to which we bring products enabled by our technologies to market . other than for collaboration revenues recognized upon cancellation or modification of an existing collaboration or for revenues generated pursuant to future strategic transactions for any of our existing platforms or programs , we expect our collaboration revenues will continue to decrease in the near term . our revenues will also depend upon our ability to maintain or improve the volume and pricing of trans ova 's and exemplar 's current product and service offerings and to develop and scale up production of new offerings from the various technologies of our subsidiaries . as we focus on our healthcare business , we anticipate that our expenses will increase substantially if , and as , we continue to advance the preclinical and clinical development of our existing product candidates and our research programs . we expect a significant period of time could pass before commercialization of our various product candidates or before the achievement of contractual milestones and the realization of royalties on product candidates commercialized under our collaborations and revenues sufficient to achieve profitability . accordingly , there can be no assurance as to the timing , magnitude , and predictability of revenues to which we might be entitled . 71 table of contents cost of products and services cost of products and services includes primarily labor and related costs , drugs and supplies used primarily in trans ova 's embryo transfer and ivf processes , livestock and feed used in production , and facility charges , including rent and depreciation . fluctuations in the price of livestock and feed have not had a significant impact on our operating margins and no derivative financial instruments are used to mitigate the price risk . research and development expenses we recognize research and development expenses as they are incurred . our research and development expenses consist primarily of : salaries and benefits , including stock-based compensation expense , for personnel in research and development functions ; fees paid to consultants and contract research organizations who perform research on our behalf and under our direction ; costs related to laboratory supplies used in our research and development efforts and acquiring , developing , and manufacturing preclinical study and clinical trial materials ; costs related to certain in-licensed technology rights or reacquired in-process research and development ; amortization of patents and related technologies acquired in mergers and acquisitions ; and facility-related expenses , which include direct depreciation costs and unallocated expenses for rent and maintenance of facilities and other operating costs . our research and development expenses are generally incurred by our operating segments and primarily relate to either costs incurred to expand or otherwise improve our technologies or the costs incurred to develop our own products and services . pgen therapeutics is progressing preclinical and clinical programs in immuno-oncology , autoimmune disorders and infectious diseases , including prgn-3005 and prgn-3006 which are both in phase 1/1b clinical trials . actobio has a portfolio of candidates available for clinical development across a number of potential indications using our actobiotics platform , including its most advanced candidate , ag019 , that is currently in a phase 1b/2a clinical trial . trans ova 's research and development activities support new and improved product and service offerings for its customers . the human biotherapeutics division supports our inxn-4001 product candidate with triple-gene and our partnered program with castle creek . other operating segment research and development primarily relates to exemplar 's research and development activities related to new and improved pig research models . the following table summarizes our research and development expenses incurred by reportable segment for the years ended december 31 , 2020 , 2019 , and 2018. replace_table_token_6_th 72 table of contents the following table reconciles research and development expenses by reportable segments to research and development expenses on the consolidated statements of operations for the years ended december 31 , 2020 , 2019 , and 2018. replace_table_token_7_th ( 1 ) includes corporate research and development expenses not allocated to operating segments , as well as certain expenses incurred to reacquire previously licensed technology rights in the year ended december 31 , 2018. the amount of research and development expenses may be impacted story_separator_special_tag increase in interest expense of $ 8.6 million associated with our convertible notes issued in july 2018. segment performance the following table summarizes segment adjusted ebitda , which is our primary measure of segment performance , for the years ended december 31 , 2019 and 2018 , for each of our reportable segments and for all other segments combined , as well as unallocated corporate costs . replace_table_token_14_th for a reconciliation of segment adjusted ebitda to net loss from continuing operations before income taxes , see `` notes to the consolidated financial statements - note 20 `` appearing elsewhere in this annual report . the following table summarizes revenues from external customers for the years ended december 31 , 2019 and 2018 , for each of our reportable segments and for all other segments combined . replace_table_token_15_th pgen therapeutics revenues for pgen therapeutics declined from 2018 to 2019 primarily due to the reacquisition of rights previously licensed to certain collaborators , which eliminated or significantly reduced collaboration revenues from research and development services provided and recognition of previously deferred revenue . 80 table of contents actobio in 2018 , actobio reacquired rights previously licensed to certain collaborators , including intrexon t1d partners , inc. , resulting in the elimination of collaboration revenues from research and development services performed in 2019. trans ova the decrease in trans ova 's segment revenues was primarily attributable to lower product revenues due to lower customer demand . human biotherapeutics human biotherapeutics was a new segment in 2019 and the revenue is associated with our collaboration with castle creek . segment adjusted ebitda includes the costs associated with our collaboration with castle creek as well as our inxn-4001 program . all other the segment adjusted ebitda of all other improved period over period due our closure of two reporting units in 2019 and write-downs of certain long-lived assets in 2018. revenues in all other declined in 2019 as result of fewer research and development services performed for collaborations with harvest start-up entities . unallocated corporate costs unallocated corporate costs decreased primarily due to an improvement in unrealized and realized appreciation ( depreciation ) on our securities portfolio of $ 36.6 million primarily due to unrealized losses on our ziopharm preferred stock in 2018 and a realized gain on the sale of our common shares held in aquabounty in october 2019 , net of a decrease in dividend income of $ 15.1 million following the return of our investment in ziopharm preferred stock to ziopharm in october 2018. additionally , consolidated costs from aquabounty decreased in 2019 due to our deconsolidation in april 2019. story_separator_special_tag roman ' , sans-serif ; font-size:10pt ; font-weight:400 ; line-height:120 % ; text-decoration : underline `` > contents during 2019 , we received proceeds of $ 111.4 million from the maturities and sales of investments , net of purchases ; $ 21.6 million proceeds from the sale of our aquabounty securities , and we used $ 37.9 million for purchases of property , plant and equipment . during 2018 , we used $ 112.7 million for purchases of short-term investments , net of maturities ; $ 41.6 million for purchases of property , plant and equipment ; and $ 16.6 million for investments in our jvs , and we received $ 15.5 million in an asset acquisition . cash flows from financing activities : during 2020 , we received $ 35.0 million proceeds from the sale of our common stock in a private placement to ts biotechnology . during 2019 , we received $ 6.6 million in net proceeds from underwritten public offerings completed by aquabounty . during 2018 , we received $ 219.9 million net proceeds from the issuance of long-term debt and $ 88.0 million net proceeds from public financings . future capital requirements we believe our existing liquid assets , including the net proceeds from our underwritten public offering in january 2021 , will enable us to fund our operating expenses and capital requirements for at least the next 12 months . our future capital requirements will depend on many factors , including : progress in our research and development programs , as well as the magnitude of these programs ; any delays or potential delays to our clinical trials as a result of the covid-19 pandemic ; the timing of regulatory approval of our product candidates and those of our collaborations ; the timing , receipt and amount of any payments received in connection with strategic transactions ; the timing , receipt , and amount of upfront , milestone , and other payments , if any , from present and future collaborators , if any ; the timing , receipt , and amount of sales and royalties , if any , from our product candidates ; the timing and capital requirements to scale up our various product candidates and service offerings and customer acceptance thereof ; our ability to maintain and establish additional collaborative arrangements and or new strategic initiatives ; the resources , time , and cost required for the preparation , filing , prosecution , maintenance , and enforcement of our intellectual property portfolio ; strategic mergers and acquisitions , if any , including both the upfront acquisition cost as well as the cost to integrate , maintain , and expand the strategic target ; the costs associated with legal activities , including litigation , arising in the course of our business activities and our ability to prevail in any such legal disputes ; and the effects , duration , and severity of the ongoing covid-19 pandemic and the actions we have taken or may take in response , any of which could significantly impact our business , operations , and financial results . until such time , if ever , as we can regularly generate positive operating cash flows , we plan to finance our cash needs through a combination of equity offerings , debt financings , government , or other third-party funding ,

liquidity and capital resources sources of liquidity we have incurred losses from operations since our inception , and as of december 31 , 2020 , we had an accumulated deficit of $ 1.8 billion . from our inception through december 31 , 2020 , we have funded our operations principally with proceeds received from private and public equity and debt offerings , cash received from our collaborators , and through product and service sales made directly to customers . as of december 31 , 2020 , we had cash and cash equivalents of $ 51.8 million and short-term investments of $ 48.3 million . in january 2021 , we closed an underwritten public offering of our common stock , resulting in net proceeds of approximately $ 121.2 million , after deducting underwriting discounts and estimated offering expenses . cash in excess of immediate requirements is typically invested primarily in money market funds and united states government debt securities in order to maintain liquidity and preserve capital . we currently generate cash receipts primarily from sales of products and services and from strategic transactions . as of december 31 , 2020 , trans ova was in compliance with the debt covenants associated with its line of credit as discussed in `` notes to the consolidated financial statements - note 12 '' appearing elsewhere in this annual report .


 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.
     ```liquidity and capital resources sources of liquidity we have incurred losses from operations since our inception , and as of december 31 , 2020 , we had an accumulated deficit of $ 1.8 billion . from our inception through december 31 , 2020 , we have funded our operations principally with proceeds received from private and public equity and debt offerings , cash received from our collaborators , and through product and service sales made directly to customers . as of december 31 , 2020 , we had cash and cash equivalents of $ 51.8 million and short-term investments of $ 48.3 million . in january 2021 , we closed an underwritten public offering of our common stock , resulting in net proceeds of approximately $ 121.2 million , after deducting underwriting discounts and estimated offering expenses . cash in excess of immediate requirements is typically invested primarily in money market funds and united states government debt securities in order to maintain liquidity and preserve capital . we currently generate cash receipts primarily from sales of products and services and from strategic transactions . as of december 31 , 2020 , trans ova was in compliance with the debt covenants associated with its line of credit as discussed in `` notes to the consolidated financial statements - note 12 '' appearing elsewhere in this annual report .
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 Suspicious Activity Report : we are also entitled to sublicensing revenues in those situations where our collaborators choose to license our technologies to other parties . as we continue to shift our focus on our healthcare business , we have and may continue to mutually terminate collaboration agreements or repurchase rights to the exclusive fields from collaborators , relieving us of any further performance obligations under the agreement . upon such circumstances or when we determine no further performance obligations are required of us under an agreement , we may recognize any remaining deferred revenue as either collaboration revenue or as a reduction of operating expense , depending on the circumstances . see `` notes to the consolidated financial statements - note 6 `` appearing elsewhere in this annual report for a discussion of changes to our significant collaborations . we generate product and service revenues primarily through sales of products or services that are created from technologies developed or owned by us . our primary current offerings arise from trans ova and include sales of advanced reproductive technologies , including our bovine embryo transfer and ivf processes and from genetic preservation and sexed semen processes , and applications of such processes to other livestock , as well as sales of livestock and embryos produced using these processes and used in production . exemplar also generates product and service revenues through the development and sale of genetically engineered miniature swine models . we recognize revenue when control of the promised product is transferred to the customer or when the promised service is completed . in future periods , in connection with our focus on healthcare , our revenues will primarily depend on our ability to advance and create our own programs and the extent to which we bring products enabled by our technologies to market . other than for collaboration revenues recognized upon cancellation or modification of an existing collaboration or for revenues generated pursuant to future strategic transactions for any of our existing platforms or programs , we expect our collaboration revenues will continue to decrease in the near term . our revenues will also depend upon our ability to maintain or improve the volume and pricing of trans ova 's and exemplar 's current product and service offerings and to develop and scale up production of new offerings from the various technologies of our subsidiaries . as we focus on our healthcare business , we anticipate that our expenses will increase substantially if , and as , we continue to advance the preclinical and clinical development of our existing product candidates and our research programs . we expect a significant period of time could pass before commercialization of our various product candidates or before the achievement of contractual milestones and the realization of royalties on product candidates commercialized under our collaborations and revenues sufficient to achieve profitability . accordingly , there can be no assurance as to the timing , magnitude , and predictability of revenues to which we might be entitled . 71 table of contents cost of products and services cost of products and services includes primarily labor and related costs , drugs and supplies used primarily in trans ova 's embryo transfer and ivf processes , livestock and feed used in production , and facility charges , including rent and depreciation . fluctuations in the price of livestock and feed have not had a significant impact on our operating margins and no derivative financial instruments are used to mitigate the price risk . research and development expenses we recognize research and development expenses as they are incurred . our research and development expenses consist primarily of : salaries and benefits , including stock-based compensation expense , for personnel in research and development functions ; fees paid to consultants and contract research organizations who perform research on our behalf and under our direction ; costs related to laboratory supplies used in our research and development efforts and acquiring , developing , and manufacturing preclinical study and clinical trial materials ; costs related to certain in-licensed technology rights or reacquired in-process research and development ; amortization of patents and related technologies acquired in mergers and acquisitions ; and facility-related expenses , which include direct depreciation costs and unallocated expenses for rent and maintenance of facilities and other operating costs . our research and development expenses are generally incurred by our operating segments and primarily relate to either costs incurred to expand or otherwise improve our technologies or the costs incurred to develop our own products and services . pgen therapeutics is progressing preclinical and clinical programs in immuno-oncology , autoimmune disorders and infectious diseases , including prgn-3005 and prgn-3006 which are both in phase 1/1b clinical trials . actobio has a portfolio of candidates available for clinical development across a number of potential indications using our actobiotics platform , including its most advanced candidate , ag019 , that is currently in a phase 1b/2a clinical trial . trans ova 's research and development activities support new and improved product and service offerings for its customers . the human biotherapeutics division supports our inxn-4001 product candidate with triple-gene and our partnered program with castle creek . other operating segment research and development primarily relates to exemplar 's research and development activities related to new and improved pig research models . the following table summarizes our research and development expenses incurred by reportable segment for the years ended december 31 , 2020 , 2019 , and 2018. replace_table_token_6_th 72 table of contents the following table reconciles research and development expenses by reportable segments to research and development expenses on the consolidated statements of operations for the years ended december 31 , 2020 , 2019 , and 2018. replace_table_token_7_th ( 1 ) includes corporate research and development expenses not allocated to operating segments , as well as certain expenses incurred to reacquire previously licensed technology rights in the year ended december 31 , 2018. the amount of research and development expenses may be impacted story_separator_special_tag increase in interest expense of $ 8.6 million associated with our convertible notes issued in july 2018. segment performance the following table summarizes segment adjusted ebitda , which is our primary measure of segment performance , for the years ended december 31 , 2019 and 2018 , for each of our reportable segments and for all other segments combined , as well as unallocated corporate costs . replace_table_token_14_th for a reconciliation of segment adjusted ebitda to net loss from continuing operations before income taxes , see `` notes to the consolidated financial statements - note 20 `` appearing elsewhere in this annual report . the following table summarizes revenues from external customers for the years ended december 31 , 2019 and 2018 , for each of our reportable segments and for all other segments combined . replace_table_token_15_th pgen therapeutics revenues for pgen therapeutics declined from 2018 to 2019 primarily due to the reacquisition of rights previously licensed to certain collaborators , which eliminated or significantly reduced collaboration revenues from research and development services provided and recognition of previously deferred revenue . 80 table of contents actobio in 2018 , actobio reacquired rights previously licensed to certain collaborators , including intrexon t1d partners , inc. , resulting in the elimination of collaboration revenues from research and development services performed in 2019. trans ova the decrease in trans ova 's segment revenues was primarily attributable to lower product revenues due to lower customer demand . human biotherapeutics human biotherapeutics was a new segment in 2019 and the revenue is associated with our collaboration with castle creek . segment adjusted ebitda includes the costs associated with our collaboration with castle creek as well as our inxn-4001 program . all other the segment adjusted ebitda of all other improved period over period due our closure of two reporting units in 2019 and write-downs of certain long-lived assets in 2018. revenues in all other declined in 2019 as result of fewer research and development services performed for collaborations with harvest start-up entities . unallocated corporate costs unallocated corporate costs decreased primarily due to an improvement in unrealized and realized appreciation ( depreciation ) on our securities portfolio of $ 36.6 million primarily due to unrealized losses on our ziopharm preferred stock in 2018 and a realized gain on the sale of our common shares held in aquabounty in october 2019 , net of a decrease in dividend income of $ 15.1 million following the return of our investment in ziopharm preferred stock to ziopharm in october 2018. additionally , consolidated costs from aquabounty decreased in 2019 due to our deconsolidation in april 2019. story_separator_special_tag roman ' , sans-serif ; font-size:10pt ; font-weight:400 ; line-height:120 % ; text-decoration : underline `` > contents during 2019 , we received proceeds of $ 111.4 million from the maturities and sales of investments , net of purchases ; $ 21.6 million proceeds from the sale of our aquabounty securities , and we used $ 37.9 million for purchases of property , plant and equipment . during 2018 , we used $ 112.7 million for purchases of short-term investments , net of maturities ; $ 41.6 million for purchases of property , plant and equipment ; and $ 16.6 million for investments in our jvs , and we received $ 15.5 million in an asset acquisition . cash flows from financing activities : during 2020 , we received $ 35.0 million proceeds from the sale of our common stock in a private placement to ts biotechnology . during 2019 , we received $ 6.6 million in net proceeds from underwritten public offerings completed by aquabounty . during 2018 , we received $ 219.9 million net proceeds from the issuance of long-term debt and $ 88.0 million net proceeds from public financings . future capital requirements we believe our existing liquid assets , including the net proceeds from our underwritten public offering in january 2021 , will enable us to fund our operating expenses and capital requirements for at least the next 12 months . our future capital requirements will depend on many factors , including : progress in our research and development programs , as well as the magnitude of these programs ; any delays or potential delays to our clinical trials as a result of the covid-19 pandemic ; the timing of regulatory approval of our product candidates and those of our collaborations ; the timing , receipt and amount of any payments received in connection with strategic transactions ; the timing , receipt , and amount of upfront , milestone , and other payments , if any , from present and future collaborators , if any ; the timing , receipt , and amount of sales and royalties , if any , from our product candidates ; the timing and capital requirements to scale up our various product candidates and service offerings and customer acceptance thereof ; our ability to maintain and establish additional collaborative arrangements and or new strategic initiatives ; the resources , time , and cost required for the preparation , filing , prosecution , maintenance , and enforcement of our intellectual property portfolio ; strategic mergers and acquisitions , if any , including both the upfront acquisition cost as well as the cost to integrate , maintain , and expand the strategic target ; the costs associated with legal activities , including litigation , arising in the course of our business activities and our ability to prevail in any such legal disputes ; and the effects , duration , and severity of the ongoing covid-19 pandemic and the actions we have taken or may take in response , any of which could significantly impact our business , operations , and financial results . until such time , if ever , as we can regularly generate positive operating cash flows , we plan to finance our cash needs through a combination of equity offerings , debt financings , government , or other third-party funding ,

