1 Institute for Immunology and Department of Basic Medical Sciences, School of Medicine, Tsinghua University, and Center for Life Sciences, Beijing, China.
2 Chinese Institute for Brain Research, Beijing, China. Electronic address: chenjian@cibr.ac.cn.
3 Institute for Immunology and Department of Basic Medical Sciences, School of Medicine, Tsinghua University, and Center for Life Sciences, Beijing, China; Beijing Key Laboratory for Immunological Research on Chronic Diseases, Beijing, China. Electronic address: wenwenzeng@tsinghua.edu.cn.