1. Department of Gastroenterology and Hepatology, Faculty of Medicine and Graduate School of Medicine Hokkaido University Sapporo Japan
2. Division of Endoscopy Hokkaido University Hospital Sapporo Japan
3. Department of Internal Medicine Kawasaki Rinko General Hospital Kawasaki Japan
4. Division of Gastroenterology and Hepatology, Department of Internal Medicine St. Marianna University School of Medicine Kawasaki Japan
5. Department of Bioinformatics St. Marianna University Graduate School of Medicine Kawasaki Japan