1 Department of Gastroenterology, Aichi Medical University School of Medicine, 1-1 Yazakokarimata, Nagakute, Aichi, 480-1195, Japan. kito@aichi-med-u.ac.jp.
2 Department of Gastroenterology, Aichi Medical University School of Medicine, 1-1 Yazakokarimata, Nagakute, Aichi, 480-1195, Japan.
3 The Research Center for Hepatitis and Immunology, National Center for Global Health and Medicine, Ichikawa, Japan.