1. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
2. Department of Internal Medicine, Eulji University School of Medicine, Seoul, Korea.
3. Department of Internal Medicine, Kangwon National University School of Medicine, Chuncheon, Korea.
4. Department of Internal Medicine, Dankook University Hospital, Cheonan, Korea.
5. Department of Pathology, Seoul National University College of Medicine, Seoul, Korea.
6. Department of General Surgery, Seoul National University College of Medicine, Seoul, Korea.