1. Department of Gastrointestinal Surgery, Graduate School of Medicine, University of Tokyo, Tokyo, Japan;
2. Department of Pathology, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan;
3. Research Center for Innovative Oncology, National Cancer Center Hospital East, Kashiwa, Japan;
4. Showa General Hospital, Kodaira, Japan; and
5. Nashville Veterans Affairs Medical Center and the Departments of Surgery and Cell and Developmental Biology, Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee