Individual CpG sites that are associated with age and life expectancy become hypomethylated upon aging.

Individual age-associated CpGs may provide biomarkers for all-cause mortality-but confounding factors need to be critically taken into consideration, and alternative methods, which facilitate more quantitative measurements at individual CpGs, might be advantageous. Our data suggest that particularly specific CpGs that become hypomethylated upon aging are indicative of biological aging.