1. Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215006, P.R. China
2. Department of Pathology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215006, P.R. China
3. Department of Gastroenterology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215006, P.R. China