1 Centre for Heart Lung Innovation, St Paul's Hospital, Vancouver, British Columbia, Canada; Division of Respiratory Medicine, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
2 Centre for Heart Lung Innovation, St Paul's Hospital, Vancouver, British Columbia, Canada; Division of Respiratory Medicine, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea.
3 Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
4 Centre for Heart Lung Innovation, St Paul's Hospital, Vancouver, British Columbia, Canada; Division of Respiratory Medicine, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada. Electronic address: don.sin@hli.ubc.ca.