Dr. William Tierney is currently David Ross Boyd Professor of Medicine at the University of Oklahoma and serves as Chief of Clinical Services for the Section of Gastroenterology. Dr. Tierney has served on several national committees including the Governing Board of the American Society for Gastrointestinal Endoscopy (ASGE) and has served as Chair of the ASGE ARIA Committee. He has published over 100 journal articles and book chapters and has a focused interest in colorectal cancer screening and the process of care for various endoscopic interventions.