1. Sano Hospital, Gastrointestinal Center, Kobe, Japan
2. Department of Medical Statistics, Toho University, Tokyo, Japan
3. University of Queensland School of Medicine, Brisbane, Australia
4. Gastroenterology, Stanford University School of Medicine, Palo Alto, California, USA
5. Department of Surgical and Molecular Pathology, Dokkyo University School of Medicine, Tochigi, Japan