1. Division of Gastroenterology and Hepatology, Department of Internal Medicine, St. Marianna University School of Medicine
2. Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine
3. Department of Surgery, Keio University School of Medicine
4. Digestive Diseases Center, International University of Health and Welfare School of Medicine
5. Department of Pathology, Keio University School of Medicine
6. Division of Gastroenterology and Hepatology, Department of Internal Medicine, Kawasaki Municipal Tama Hospital
7. Tama Medical Practice Center, Kawasaki Municipal Tama Hospital