Currently Independent Director, co-founder and/or consultant to private and public biotechnology companies. Most recently Sr. VP/Chief Medical & Development Officer, Hyperion Therapeutics, where he was responsible for the development of glycerol phenylbutyrate (GPB, RAVICTI^®), approved for treatment of urea cycle disorders in the US (2013), Europe and Canada (2015/6) and the successful phase 2 trial of GPB for hepatic encephalopathy. Was inventor/co-inventor on Hyperion IP, a member of Hyperion’s road show team leading to its 2012 IPO, 2013 secondary offering and May 2015 sale to Horizon Pharma. Previously held senior positions at Novartis, Chiron and the Univ. of CA, San Francisco (UCSF), where he was Professor of Medicine, Chief of Gastroenterology, an NIH-funded investigator for two decades, Editor of Sleisenger & Fordtran’s Textbook of Gastroenterology and helped launch the UCSF liver transplant program. Author of over 200 research and review articles and multiple issued and pending patents, he served as Assoc. Editor of Gastroenterology, Editor-in-Chief of the Journal of Clinical Investigation and President of the American Society for Clinical Investigation. He is Board Certified in Internal Medicine and Gastroenterology and was a member of the National Board of Directors of the American Liver Foundation from 2005-2013. He is currently a member of the External Advisory Board for the Clinical and Translational Science Program at Northwestern’s Feinberg School of Medicine, President of Northwestern’s Medical Alumni Board and a member of the President’s Council Executive Committee for the J. David Gladstone Institute.