1. Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
2. Department of Internal Medicine, CHA Gangnam Medical Center, CHA University School of Medicine, Seoul, Korea.
3. Department of Internal Medicine and Lung Institute, Seoul National University College of Medicine, Seoul, Korea.
4. Department of Internal Medicine, Kyung Hee University School of Medicine, Seoul, Korea.
5. Department of Internal Medicine, Sungkyunkwan University School of Medicine, Seoul, Korea.
6. Department of Internal Medicine, Hanyang University Guri Hospital, Hanyang University College of Medicine, Guri, Korea.
7. Department of Internal Medicine, Ewha Womans University School of Medicine, Seoul, Korea.
8. Department of Internal Medicine, Dankook University College of Medicine, Cheonan, Korea.
9. Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
10. Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.