1. Division of Research and Development for Minimally Invasive Treatment, Cancer Center, Keio University School of Medicine, Tokyo, Japan
2. Department of Gastroenterology, National Hospital Organization, Tokyo Medical Center, Tokyo, Japan
3. Department of Gastroenterology, National Hospital Organization, Fukuyama Medical Center, Fukuyama, Hiroshima, Japan
4. Department of Gastroenterology and Hepatology, Gunma University Graduate School of Medicine, Maebashi, Japan
5. Department of Pathology, Keio University School of Medicine, Tokyo, Japan
6. Center for Diagnostic and Therapeutic Endoscopy, Keio University School of Medicine, Tokyo, Japan
7. Department of Gastroenterology, Nippon Meidal School, Graduate School of Medicine Tokyo, Japan
8. Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan