Dr. Lewis T. Williams, also known as Rusty, M.D, Ph.D, founded Five Prime Therapeutics, Inc. in December 2001 and has been its Executive Chairman since January 2018. Dr. Williams served as the President and CEO of Five Prime Therapeutics, Inc. from August 2011 to December 2017. Dr. Williams previously served as the Chairman of Five Prime Therapeutics, Inc. from January 2012 to January 2018. He served as the Chief Scientific Officer at Chiron Corporation since 1998 and also served as its President. He joined Chiron Corporation in August 1994 as Senior Vice President and President at Chiron Technologies (now called Chiron Research and Development). Prior to joining Five Prime, Dr. Williams spent seven years at Chiron Corporation, a biopharmaceutical company, now Novartis Vaccines and Diagnostics, Inc., Dr. Williams was a Howard Hughes Medical Institute investigator at the University of California, San Francisco. Earlier in his career he was on the faculty of Harvard Medical School. He was a Co-Founder of COR Therapeutics Inc. He founded Fiveprime Therapeutics Inc., in 2002 and served as its Executive Chairman from July 2003 to January 2012. He serves as a Director at Fiveprime Therapeutics Inc., Comedicus Inc. and Berklee College of Music. He has been a Director of Juvaris BioTherapeutics Inc. since 2007. He served as a Director of Chiron Corporation from May 1999 to 2001. He serves as a Member of Scientific Advisory Board of Fiveprime Therapeutics Inc. He served as a Member of Scientific Advisory Board of Veracyte, Inc. He has been a Director at Protagonist Therapeutics, Inc. since June 08, 2017. He served as a Director of Beckman Coulter Inc. from October 23, 2009 to June 20, 2011. He served as a Director of COR Therapeutics Inc. from 1988 to August 1994. From 1992 to 1994, Dr. Williams served on the Scientific Advisory Board of Geron Corporation and Fiveprime Therapeutics, Inc. From 1988 to August 1994, he was a Professor of Medicine at the University of California, San Francisco. He served as Director of the University's Cardiovascular Research Institution and Daiichi Research Center. Prior to joining UCSF, he was on the faculty of Harvard Medical School. He served as Executive Chairman of Five Prime Therapeutics, Inc. from July 2003 to January 2012. He has been a Director of Five Prime Therapeutics, Inc. since January 2002. He served as a Trustee of Duke University until May 2009. He is a member of the National Academy of Sciences and a fellow of the American Academy of Arts & Sciences. Dr. Williams received his M.D. and Ph.D. degrees from Duke University. He holds B.S. from Rice University. He trained in Internal Medicine and Cardiology at the Massachusetts General Hospital.