1. Department of Obstetrics and Gynecology, Affiliated Hospital of Weifang Medical University, Weifang, Shandong, China
2. Department of Gynecologic Oncology, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing Maternal and Child Health Care Hospital, Beijing, China
3. Department of Pathology, Affiliated Hospital of Weifang Medical University, Weifang, Shandong, China.