1. Department of Digestive Tract and General Surgery, Saitama Medical Center, Saitama Medical University, Saitama, Japan
2. Department of Pathology, International Medical Center, Saitama Medical University, Saitama, Japan
3. Department of Pathology, Saitama Medical Center, Saitama Medical University, Saitama, Japan
4. Department of Surgery, Tokyo Medical and Dental University, Tokyo, Japan
5. Research Team for Geriatric Diseases (Human Tissue Research Group), Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan