Footnotes

• Handling editor Josef S Smolen

• FRS and FC contributed equally.

• Contributors FRS and FC discussed the topic of the letter, did the literature search and drafted the manuscript. MDF and FC reviewed and approved 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 and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.

• Patient consent for publication Not required.

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