1 State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, China.
2 Wei-jie Guan and Xiao-rong Han contributed equally.
3 Pneumology Unit, Platon Hospital, Barcelona, Spain.
4 Pneumology Dept, University and Politechnic La Fe Hospital, Valencia, Spain.