Putting epigenetic aging clocks on trial.

Steve Horvath reviews in Nature Medicine a new study offering the first systematic test of whether DNA methylation clocks behave as a proper surrogate endpoint for aging, responding to genuine clinical benefit while remaining stable when there is none. The News & Views piece, published 21 August 2026 in volume 32, pages 3144–3145, discusses a report card approach to aging-clock surrogacy and cites related 2026 work in Nature Medicine and Nature Aging.