1. Department of Internal Medicine, Wonkwang University College of Medicine, Iksan, Korea
2. Institution of Wonkwang Medical Science, Wonkwang University College of Medicine, Iksan, Korea
3. Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
4. Center of Hepatobiliary and Pancreatic Disease, Department of Internal Medicine, Changwon Hanmaeum Hospital, Hanyang University College of Medicine, Changwon, Korea
5. Department of Internal Medicine, Jeju National University College of Medicine, Jeju, Korea