1 Division of Gastroenterology, Department of Internal Medicine, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
2 Department of Hospital Pathology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
3 Division of Gastroenterology, Department of Internal Medicine, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea. kijoons@catholic.ac.kr.
4 Division of Gastroenterology, Department of Internal Medicine, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.