1. Department of Internal Medicine, Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Republic of Korea
2. Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea
3. Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Republic of Korea
4. Department of Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea