1. Division of Gastroenterology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
2. Department of Clinical Pathology, Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Bucheon, Korea
3. Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
4. Department of Internal Medicine, Chungbuk National University College of Medicine, Cheongju, Korea
5. Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
6. Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Korea