1. Peking University Stem Cell Research Center and China National Center for International Research, Beijing 100191, People's Republic of China.
2. Department of Cell Biology, Peking University Health Science Center, Beijing 100191, People's Republic of China.
3. The Department of Genecology & Obstetrics, the Fourth Military Medical University Tangdu Hospital, Xian 710038, People's Republic of China.
4. Department of Medicine, Division of Cardiology, Stanford University School of Medicine, Stanford, California.