Footnotes

• ANT and AB are joint first authors.

• DDC and SSH are joint senior authors.

• Twitter @lungdiagnosis

• Contributors SH, DC and AK devised the pathway. AT, JB, HJ, SB and AB revised the pathway, AT, SH and DC wrote the manuscript.

• Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

• Competing interests None declared.

• Patient consent for publication Not required.

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