Read the following texts and table with financial data from an S&P 500 earnings report carefully.Based on the question-answer history (if provided), answer the last question. The answer may require mathematical calculation based on the data provided.


recognition of deferred revenue related to sanofi-aventis 2019 $ 85.0 million up-front payment decreased in 2010 compared to 2009 due to the november 2009 amendments to expand and extend the companies 2019 antibody collaboration . in connection with the november 2009 amendment of the discovery agreement , sanofi-aventis is funding up to $ 30 million of agreed-upon costs incurred by us to expand our manufacturing capacity at our rensselaer , new york facilities , of which $ 23.4 million was received or receivable from sanofi-aventis as of december 31 , 2010 . revenue related to these payments for such funding from sanofi-aventis is deferred and recognized as collaboration revenue prospectively over the related performance period in conjunction with the recognition of the original $ 85.0 million up-front payment . as of december 31 , 2010 , $ 79.8 million of the sanofi-aventis payments was deferred and will be recognized as revenue in future periods . in august 2008 , we entered into a separate velocigene ae agreement with sanofi-aventis . in 2010 and 2009 , we recognized $ 1.6 million and $ 2.7 million , respectively , in revenue related to this agreement . bayer healthcare collaboration revenue the collaboration revenue we earned from bayer healthcare , as detailed below , consisted of cost sharing of regeneron vegf trap-eye development expenses , substantive performance milestone payments , and recognition of revenue related to a non-refundable $ 75.0 million up-front payment received in october 2006 and a $ 20.0 million milestone payment received in august 2007 ( which , for the purpose of revenue recognition , was not considered substantive ) . years ended bayer healthcare collaboration revenue december 31 . <table class='wikitable'><tr><td>1</td><td>bayer healthcare collaboration revenue</td><td>bayer healthcare collaboration revenue</td><td>-</td></tr><tr><td>2</td><td>( in millions )</td><td>2010</td><td>2009</td></tr><tr><td>3</td><td>cost-sharing of regeneron vegf trap-eye development expenses</td><td>$ 45.5</td><td>$ 37.4</td></tr><tr><td>4</td><td>substantive performance milestone payments</td><td>20.0</td><td>20.0</td></tr><tr><td>5</td><td>recognition of deferred revenue related to up-front and other milestone payments</td><td>9.9</td><td>9.9</td></tr><tr><td>6</td><td>total bayer healthcare collaboration revenue</td><td>$ 75.4</td><td>$ 67.3</td></tr></table> cost-sharing of our vegf trap-eye development expenses with bayer healthcare increased in 2010 compared to 2009 due to higher internal development activities and higher clinical development costs in connection with our phase 3 copernicus trial in crvo . in the fourth quarter of 2010 , we earned two $ 10.0 million substantive milestone payments from bayer healthcare for achieving positive 52-week results in the view 1 study and positive 6-month results in the copernicus study . in july 2009 , we earned a $ 20.0 million substantive performance milestone payment from bayer healthcare in connection with the dosing of the first patient in the copernicus study . in connection with the recognition of deferred revenue related to the $ 75.0 million up-front payment and $ 20.0 million milestone payment received in august 2007 , as of december 31 , 2010 , $ 47.0 million of these payments was deferred and will be recognized as revenue in future periods . technology licensing revenue in connection with our velocimmune ae license agreements with astrazeneca and astellas , each of the $ 20.0 million annual , non-refundable payments were deferred upon receipt and recognized as revenue ratably over approximately the ensuing year of each agreement . in both 2010 and 2009 , we recognized $ 40.0 million of technology licensing revenue related to these agreements . in addition , in connection with the amendment and extension of our license agreement with astellas , in august 2010 , we received a $ 165.0 million up-front payment , which was deferred upon receipt and will be recognized as revenue ratably over a seven-year period beginning in mid-2011 . as of december 31 , 2010 , $ 176.6 million of these technology licensing payments was deferred and will be recognized as revenue in future periods . net product sales in 2010 and 2009 , we recognized as revenue $ 25.3 million and $ 18.4 million , respectively , of arcalyst ae net product sales for which both the right of return no longer existed and rebates could be reasonably estimated . the company had limited historical return experience for arcalyst ae beginning with initial sales in 2008 through the end of 2009 ; therefore , arcalyst ae net product sales were deferred until the right of return no longer existed and rebates could be reasonably estimated . effective in the first quarter of 2010 , the company determined that it had .
Question: what is the recognized revenue in 2010, in millions?
Answer: 25.3
Question: what about in 2009, in millions?
Answer: 18.4
Question: what is the net increase?

43.7