1. Department of Gastroenterology, The Affiliated People's Hospital of Ningbo University, Ningbo, Zhejiang 315000, P.R. China
2. Department of Pathology, The Affiliated People's Hospital of Ningbo University, Ningbo, Zhejiang 315000, P.R. China
3. Department of Colorectal Surgery, Ningbo Medical Center Lihuili Hospital, Ningbo, Zhejiang 315000, P.R. China