Dr. Harrison is a Visiting Professor of Hepatology at the Radcliffe Department of Medicine, University of Oxford. He is also the Medical Director for Pinnacle Clinical Research and the President of Summit Clinical Research. Dr. Harrison is a peer-reviewer for more than 20 medical journals. He is internationally known for studies in hepatitis C and non-alcoholic fatty liver disease with more than 200 peer reviewed publications in these fields. Dr. Harrison previously served as a Professor of Medicine at the Uniformed Services University of the Health Sciences and as Associate Editor for Hepatology and Alimentary Pharmacology and Therapeutics. Most recently, Dr. Harrison served as a Colonel in the United States Army, retiring in 2016 to conclude 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. 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 and a 4th year advanced liver disease fellowship at Saint Louis University. He is board certified in both Internal Medicine and Gastroenterology.