Tatsuya Koshitani1, Shuji Nakagawa1,2, Yoshito Itoh3. 1. Department of Gastroenterology, Japan Community Healthcare Organization Kobe Central Hospital, Kobe, Japan. 2. Nakagawa Medical Clinic, Kobe, Japan. 3. Department of Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.