1. Health Screening and Promotion Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
2. Department of Gastroenterology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
3. Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
4. Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
5. Department of Biochemistry and Molecular Biology, University of Ulsan College of Medicine, Seoul, Korea
6. Asan Institute for Life Sciences, Asan Medical Center, Seoul, Korea