1. Department of Gastroenterology, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
2. Department of Hepatobiliary and Pancreatic Medicine, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
3. Department of Pathology, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China