1. Department of Histology and Embryology, Chongqing Three Gorges Medical College, Wanzhou, Chongqing 404120, China
2. Department of Embryo Laboratory, Changsha Reproductive Medical Hospital, Changsha, Hunan 410000, China
3. Department of Infectious Disease, Three Gorges Hospital of Chongqing University, Chongqing University, Wanzhou, Chongqing 404000, China
4. Hunan Province Key Laboratory of Tumor Cellular & Molecular Pathology, Cancer Research Institute, University of South China, Hengyang, Hunan 421001, China