1. Ewha Medical Research Center, Seoul, Korea.
2. Department of Internal Medicine, Daejin Medical Center, Pundang Jesaeng General Hospital, Seoul, Korea.
3. Department of Internal Medicine, Ewha Womans University College of Medicine, Seoul, Korea.
4. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
5. Department of Internal Medicine, Dongguk University College of Medicine, Seoul, Korea.
6. Department of Pathology, Ewha Womans University College Medicine, Seoul, Korea.