1. Department of Obstetrics and Gynecology, Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE and State Key Laboratory of Biotherapy, West China Second University Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, P. R. China.
2. Department of Neurology, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and National Collaborative Innovation Center, Chengdu 610041, P. R. China.
3. Department of Gynecology, Huzhou Maternity & Child Health Care Hospital, Huzhou, P. R. China.
4. Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
5. Department of Biomedical Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong, P. R. China.
6. Department of Pathology, West China Second University Hospital, Sichuan University, Chengdu, P. R. China.