Figure 1.

Relative quantification of age-dependent LINE-1 methylation by IDLN-MSP in cellular and cfDNA. Correlation between age and DNA methylation of LINE-1 promoter region in cellular DNA (A, B) and cell-free DNA (C, D) derived from blood plasma of the indicated numbers of donors (N). The regression lines are colored in red and represent Pearson’s correlation coefficients (R²). Mean values of global DNA methylation at LINE-1 retrotransposons in cellular DNA and cell-free DNA from blood plasma by age subgroups (B, D). Mean values were compared by two-sample Student’s t-test with a significance threshold p < 0.05. 19–30 to 31–40 years, p = 0.01, 19–30 to 41–50 years, p = 0.0000043026, 19–30 to 51–60 years, p = 0.0000000049, 31–40 to 41–50 years, p = 0.1897896039, 31–40 to 51–60 years, p = 0.0040846031, 1D).