1. Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Korea
2. Biomedical Research Institute, Seoul National University Hospital, Seoul 110-744, Korea
3. Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul 110-799, Korea
4. Department of Internal Medicine, Seoul National University College of Medicine, Seoul 110-799, Korea