Footnotes

• Contributors MBF and DVF carried out wet lab experiments. AMF, AR and AGN carried out histopathology assessment. EL conceived and managed the study and also performed statistical analysis. All coauthors contributed into manuscript preparation.

• Funding The project was funded by The Peter and Mary Fu Foundation, Point Hope Group, STEMCELL Technologies, Affymetrix and supported by the National Institute of Health Research Respiratory Disease Biomedical Research Unit at the Royal Brompton and Harefield NHS Foundation Trust and Imperial College London.

• Competing interests None declared.

• Patient consent Obtained.

• Ethics approval National Institute of Health Research Respiratory Disease Biomedical Research Unit at the Royal Brompton and Harefield NHS Foundation Trust.

• Provenance and peer review Not commissioned; internally peer reviewed.