1. Division of Gastroenterology, Department of Internal Medicine, Soonchunhyang University College of Medicine, Cheonan, Korea.
2. Division of Gastroenterology, Department of Internal Medicine, Kyung Hee University School of Medicine, Seoul, Korea.
3. Department of Internal Medicine and Liver Research Institute, Seoul National University Hospital, Seoul, Korea.
4. Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
5. Institute for Digestive Research, Soonchunhyang University Seoul Hospital, Soonchunhyang University College of Medicine, Seoul, Korea.