1. Department of Internal Medicine; Hanyang University Guri Hospital, Hanyang University College of Medicine; Guri Korea
2. Department of Pathology, Severance Hospital; Yonsei University College of Medicine; Seoul Korea
3. Division of Gastroenterology, Department of Internal Medicine, Severance Hospital, Institute of Gastroenterology; Yonsei University College of Medicine; Seoul Korea
4. Department of Surgery, Severance Hospital; Yonsei University College of Medicine; Seoul Korea
5. Division of Medical Oncology, Department of Internal Medicine; Yonsei University College of Medicine; Seoul Korea