1 Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, National Clinical Research Center for Respiratory Diseases, China-Japan Friendship Hospital, Beijing, China; Department of Respiratory Medicine, Capital Medical University, Beijing, China; Institute of Respiratory Medicine, Chinese Academy of Medical Science, Beijing, China.
2 Tsinghua University School of Medicine, Beijing, China.
3 Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, National Clinical Research Center for Respiratory Diseases, China-Japan Friendship Hospital, Beijing, China; Department of Respiratory Medicine, Capital Medical University, Beijing, China; Institute of Respiratory Medicine, Chinese Academy of Medical Science, Beijing, China; Tsinghua University-Peking University Joint Center for Life Sciences, Beijing, China. Electronic address: caobin_ben@163.com.