1. Department of Gynecology and Obstetrics , Liaocheng People's Hospital and Liaocheng Clinical School of Shandong First Medical University , Liaocheng , Shandong , China
2. Department of Pathology , Affiliated Hospital of Qingdao University , Qingdao , Shandong , China
3. Institute of Tissue Engineering and Regenerative Medicine , Liaocheng People's Hospital and Liaocheng Clinical School of Shandong First Medical University , Liaocheng , Shandong , China