1. Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Peking University , Beijing 100871 , China
2. Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University , Beijing 100871 , China
3. Peking University People's Hospital, Peking University Institute of Hematology, National Clinical Research Center for Hematologic Disease , Beijing 100871 , China