 In 2008 Acceleron and Celgene started a partnership to jointly develop and market ACE-011 in which Celgene paid Acceleron $50 million up front and bought $5 million of Acceleron stock, and agreed to buy $7 million more in stock if Acceleron went public, and agreed to pay up to $510 million in milestones.In a separate deal done at the same time, Celgene acquired an option to license three products in Acceleron's pipeline directed to cancer and cancer-related bone loss.In 2011 Acceleron extended its their partnership with Celgene to include ACE-536, a development candidate for anemia; Celgene paid $25 million upfront, with potential downstream payments of $217 million in milestones and royalties over 10%.