1. Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
2. Renal Research Institute, Seoul National University College of Medicine, Seoul, Korea.
3. Clinical Research Institute, Seoul National University Hospital, Seoul, Korea.
4. Biotechnology Center, Pohang University of Science and Technology, Pohang, Korea.
5. Department of Internal Medicine, Yeungnam University College of Medicine, Daegu, Korea.
6. Department of Internal Medicine, Chungnam National University College of Medicine, Daejeon, Korea.
7. Department of Internal Medicine, Korea University Ansan Hospital, Ansan, Korea.