1. Department of Infectious Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China
2. Department of Infectious Diseases, Beijing Friendship Hospital, Capital Medical University, Beijing, China
3. Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China
4. Tsinghua-Peking Center for Life Sciences, Beijing 100084, China