Footnotes

• Handling editor Tahir S Pillay.

• Correction notice This article has been corrected since it was published Online First. The title has been updaed.

• Contributors PJT conceived the submission, discussing this before AR developed the concept further and wrote the initial draft. Both authors discussed and contributed to the final 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.

• Provenance and peer review Commissioned; internally peer reviewed.