1. Department of Endoscopy, Hiroshima University Hospital, Hiroshima, Japan.
2. Department of Gastroenterology, Hiroshima University Hospital, Hiroshima, Japan.
3. Division of Regeneration and Medicine Center for Translational and Clinical Research, Hiroshima University Hospital, Hiroshima, Japan.
4. Department of Health and Science, Prefectural University of Hiroshima, Hiroshima, Japan.
5. Department of Anatomical Pathology, Hiroshima University Hospital, Hiroshima, Japan.