Researchers developed 38 sex-specific biological aging clocks across 15 organ systems, finding differences between females and males in genetic architecture, molecular signatures, disease associations, and mortality patterns. Brain aging clocks were linked to progression from mild cognitive impairment to Alzheimer’s disease in both sexes and to sex-dependent cognitive trajectories among solanezumab-treated A4 participants, while the authors stressed that sex-pooled and sex-interaction models remain complementary approaches.