1. Department of Surgery, Seoul National University Hospital & College of Medicine, Seoul, Korea.
2. Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.
3. Division of Surgery, Thyroid Center, Seoul National University Cancer Hospital, Seoul, Korea.
4. Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, Korea.
5. Department of Biomedical Science, Seoul National University Graduate School, Seoul, Korea.