Footnotes

• Handling editor Runjan Chetty.

• Twitter @drkaushik_m

• Contributors NG involved in laboratory work-up, measured various parameters of biopsies and wrote the manuscript. KM codesigned the experiments, analysed the data, corrected and approved the final version of the manuscript. PS had the concept of the work, codesigned the experiments, corrected and approved the final version of 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; internally peer reviewed.