1. Department of Obstetrics and Gynecology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
2. Center for Reproductive Medicine, Department of Obstetrics and Gynecology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
3. Department of Pathology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
4. Department of Laboratory Medicine, Jiangsu Key Laboratory for Molecular Medicine, Nanjing University Medical School, Nanjing, China
5. Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
6. Department of Obstetrics, Gynecology and Reproductive Sciences, Center for Reproductive Sciences, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, United States