1Division of Gastroenterology, Tohoku University Graduate School of Medicine, Sendai, Japan
2Division of Gastroenterology and Hepatology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan
Copyright © 2020 Korean Society of Gastrointestinal Endoscopy
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Conflicts of Interest: The authors have no financial conflicts of interest.
Authors’ contribution
Conceptualization: Waku Hatta Supervision: Takuji Gotoda, Atsushi Masamune Writing-original draft: WH Writing-review&editing: TG, AM