1. Department of Hepatobiliary Surgery, Qilu Hospital of Shandong University, Jinan, Shandong 250012, P.R. China
2. Department of Pathology, Qilu Hospital of Shandong University, Jinan, Shandong 250012, P.R. China
3. Department of Urology Surgery, Hospital of Shandong University, Jinan, Shandong 250012, P.R. China