1. Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
2. Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea
3. Seoul National University College of Medicine, Seoul, Korea
4. Department of Pathology, Seoul National University Bundang Hospital, Seongnam, Korea
5. Receptor Cell Biology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD 20852, USA