CLOCK and Alzheimer disease: As such, Cortical clock estimations of DNAm age stand as a considerably better predictor of patients developing pathologic Alzheimer’s disease than Horvath’s clock estimations and as the sole epigenetic clock, among Horvath’s clock, Hannum’s clock, PhenoAge, and GrimAge, that significantly associated to clinical phenotypes of brain function and cognitive decline (Grodstein et al., 2021).