Hiroshi Mashimo is currently Chief of Gastroenterology at the VA Boston Healthcare System, Assistant Professor of Medicine at Harvard Medical School and Adjunct Assistant Professor Of Medicine at Boston University School of Medicine. He obtained his A.B. at Harvard College and his M.S., M.D. and Ph.D. degrees at Albert Einstein College of Medicine. He completed his medical internship, residency, and gastroenterology fellowship at Massachusetts General Hospital. His interest in molecular physiology led to advanced research and clinical training at Harvard Medical School, with Dr Daniel K. Podolsky and Dr Mark C. Fishman at Massachusetts General Hospital, and with Dr Raj K. Goyal at Beth Israel Hospital. His pioneering work using genetically altered mice models to understand basic gastrointestinal physiology has led to important understandings of the distinct roles of various mediators such as nitric oxide synthases and vasoactive intestinal peptides in the field of gastrointestinal motility. He has continued his interest in clinical gastrointestinal motility as Director of the Swallowing and Motility Disorders services at the VA Boston Healthcare, and is involved with training and teaching of students, residents and fellows at Brigham and Women’s Hospital, the VA Boston Healthcare, and Harvard Medical School. He has published numerous original and review articles in various medical and scientific journals.