1. Division of Gastrointestinal Surgery, Department of Surgery, Pusan National University Yangsan Hospital, Yangsan, Korea
2. Department of Surgery, Pusan National University Yangsan Hospital, Yangsan, Korea
3. Department of Pathology, School of Medicine, Pusan National University, Pusan National University Yangsan Hospital, Yangsan, Korea
4. Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea
5. Pusan National University, School of Medicine, Busan, Korea.