Related Party Transactions	12 Months Ended
Related Party Transactions	Dec. 31, 2014
Related Party Transactions [Abstract]
Related Party Transactions	16. Related Party Transactions Our former President and Chief Executive Officer, who is currently a member of our board of directors, is also a co-founder and member of the board of directors of Global Blood Therapeutics, Inc. (“Global Blood”), and a member of the board of directors of MyoKardia, Inc. (“MyoKardia”). In November 2012, we entered into Master Services Agreements with Global Blood and MyoKardia under which we provide certain consulting, preclinical, laboratory and clinical research related services to each of these companies. For the years ended December 31, 2014, 2013 and 2012, we recorded a reduction in research and development expense of $594,000, $816,000 and $57,000, respectively, related to owed to us by Global Blood and Myokardia under the Master Services Agreements. As of December 31, 2014 and 2013, receivables from these related parties in the amount of $40,000 and $394,000 , respectively, are included in prepaid expenses and other current assets on the consolidated balance sheet.

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

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