Acceleron Pharma, Inc. (NASDAQ:XLRN), a clinical stage biopharmaceutical company focused on the discovery, development and commercialization of novel protein therapeutics for cancer and rare diseases, today announced that John Knopf, Ph.D., Chief Executive Officer of Acceleron will ring The NASDAQ Stock Market Closing Bell on November 5, 2013, at 4:00 PM EST. Dr. Knopf will be joined by the Acceleron management team, Acceleron employees and other colleagues and friends to celebrate the Company’s progress and the completion of its IPO in September of 2013, which raised net proceeds of approximately $97 million. The event will be broadcast on the major business networks and a live webcast of The NASDAQ Closing Bell can be accessed at: http://www.nasdaq.com/about/marketsitetowervideo.asx. About Acceleron Acceleron is a clinical stage biopharmaceutical company focused on the discovery, development and commercialization of novel protein therapeutics for cancer and rare diseases. The company is a leader in understanding the biology of the Transforming Growth Factor-Beta (TGF-β) protein superfamily, a large and diverse group of molecules that are key regulators in the growth and repair of tissues throughout the human body, and in targeting these pathways to develop important new medicines. Acceleron has built a highly productive R&D platform that has generated innovative clinical and preclinical protein therapeutic candidates with novel mechanisms of action. These protein therapeutic candidates have the potential to significantly improve clinical outcomes for patients with cancer and rare diseases. For more information, please visit www.acceleronpharma.com.