Footnotes

• Contributors KC and KI identified the significance, and wrote and edited the manuscript. TK and RK edited 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 KC received lecture honoraria from ETHICON (Tokyo, Japan), TERUMO (Tokyo, Japan), and Chugai Pharmaceutical Co. (Tokyo, Japan). RK received research funding from Yakult Pharmaceutical Industry Co. (Tokyo, Japan) and Chugai Pharmaceutical Co. (Tokyo, Japan), as well as lecture honoraria from Japan Vaccine Co. (Tokyo, Japan), MSD Japan (Tokyo, Japan), and Chugai Pharmaceutical Co. (Tokyo, Japan). The remaining authors declare no conflicts of interest.

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