1. Department of Internal Medicine CHA Gangnam Medical Center, CHA University School of Medicine Seoul Korea
2. Division of Gastroenterology and Hepatology Department of Internal Medicine Seoul National University College of Medicine, Seoul Metropolitan Government Boramae Medical Center Seoul Korea
3. Department of Pathology Seoul National University College of Medicine, Seoul National University Hospital Seoul Korea
4. Division of Gastroenterology and Hepatology Stanford University School of Medicine Stanford California