1. Department of Epidemiology, Seoul National University School of Public Health, Seoul, Korea.
2. Center for Immunology and Pathology, Korea National Institute of Health, Seoul, Korea.
3. Department of Medicine, Seoul National University College of Medicine, Seoul, Korea.
4. Department of Family Medicine, Seoul National University College of Medicine, Seoul, Korea.
5. JW Lee Center for Global Medicine, Seoul National University College of Medicine, Seoul, Korea.