1. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
2. Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
3. Department of Pathology, Seoul National University Hospital, Seoul, Korea.
4. Healthcare System Gangnam Center, Seoul National University Hospital, Seoul, Korea.
5. Medical Research Collaborating Center, Seoul National University Hospital, Seoul, Korea.
6. Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University College of Medicine, Seoul, Korea.
7. Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.