1. Gastroenterology, Toyoshima Endoscopy Clinic
2. Department of Gastroenterology and Hepatology, International University of Health and Welfare, Mita Hospital
3. Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo
4. Division of Gastroenterology and Hepatology, Department of Internal Medicine, Tokai University School of Medicine
5. Laboratory of Molecular Medicine, Human Genome Center, Institute of Medical Science, The University of Tokyo