Stephen A Harrison, MD, is the Founder and Chairman of Pinnacle Clinical Research and Co-Founder and Chairman of Summit Clinical Research, LLC in San Antonio, Texas. Dr Harrison earned his medical degree from the University of Mississippi School of Medicine. He completed his internal medicine residency and gastroenterology fellowship at Brooke Army Medical Center before completing a 4-year advanced liver disease fellowship at Saint Louis University. Dr Harrison served as a Professor of Medicine at the Uniformed Services University of the Health Sciences and is currently a Visiting Professor of Hepatology at Radcliffe Department of Medicine, University of Oxford.

Dr Harrison also served as a Colonel in the United States Army. Retiring in 2016, he concluded more than 20 years of dedicated service to his country. During his army tenure, he served as the Director of Graduate Medical Education at Brooke Army Medical Center, Associate Dean for the San Antonio Uniformed Services Health Education Consortium and Gastroenterology Consultant to the Army Surgeon General. He is a past Associate Editor for Hepatology and Alimentary Pharmacology and Therapeutics. He is internationally known for his work in non-alcoholic fatty liver disease (NAFLD) with over 350 peer-reviewed publications in top-tier journals including the New England Journal of Medicine, Nature Medicine, Lancet, Lancet Gastroenterology and Hepatology, Gastroenterology, Journal of Hepatology and Hepatology. He has an H-Index of 104 with close to 50,000 citations.