1. The First Clinical Medical College of Lanzhou University, Lanzhou, Gansu, China
2. Key Laboratory of Gynecological Oncology of Gansu Province, Lanzhou, Gansu, China
3. College of Basic Medicine, Dalian Medical University, Dalian, Liaoning, China
4. Department of Obstetrics and Gynecology, First Hospital of Lanzhou University, Lanzhou, Gansu, China