Dr. Sharp, a noted molecular biologist with a focus on the genetic causes of cancer, shared the 1993 Nobel Prize in Physiology or Medicine for his discovery of “split genes” — the finding that genes could be composed of several separate segments within DNA. His lab now focuses on the therapeutic potential of RNA interference, small RNA molecules that can switch genes on and off. He has co-founded two companies: Biogen (now Biogen Idec) and Alnylam Pharmaceuticals. He received a Ph.D. in chemistry from the University of Illinois at Urbana-Champaign and is an elected member of the National Academy of Sciences, the Institute of Medicine, AAAS, the American Academy of Arts and Sciences, the American Philosophical Society, and a foreign fellow of the Royal Society (U.K.).