1. Department of Internal Medicine, Inje University Busan Paik Hospital, Inje University College of Medicine, Busan, Korea.
2. Institute for Digestive Research, Digestive Disease Center, Soonchunhyang University Hospital, Soonchunhyang University College of Medicine, Seoul, Korea.
3. Department of Internal Medicine, Hallym University College of Medicine, Seoul, Korea.
4. Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.