1. Department of Oncology, Jinan Central Hospital Affiliated to Shandong University, Jinan, Shandong 250013, P.R. China
2. Weifang Medical College, Weifang, Shandong 261031, P.R. China
3. Graduate School, Taishan Medical University, Xintai, Shandong 271200, P.R. China
4. Department of Pathology, Jinan Central Hospital Affiliated to Shandong University, Jinan, Shandong 250013, P.R. China