1. Department of Internal medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
2. Department of Internal Medicine, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea
3. Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
4. Department of Internal Medicine, Digestive Disease Research Institute, Wonkwang University College of Medicine, Iksan, Korea
5. Department of Gastroenterology, Ajou University School of Medicine, Suwon, Korea
6. Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea