Figure 1.

Simplified plots illustrating the concept of age-associated and age-varying methylation patterns. a) In age-associated methylation patterns, the average methylation level changes with age while the variability stays unchanged. b) In age-varying methylation patterns, the variance between individuals changes with age while the average methylation level does not change. c) In age-associated and age-varying methylation patterns, both average methylation level and between-subject variance change with age. Lines represent individual changes in methylation levels over time.