mRNA levels of genes harbouring age-modified CpG sites based on the FANTOM5 consortium data. (A) CAGE-defined TSS expression profiles for the age-methylated genes NGEF, SEPT5 and PDE2A in purified primary leukocytes and brain tissues. (B) CAGE-defined TSS expression profiles for the age-demethylated genes PTGER4 and PRDM16 and the age-methylated gene SNED1; mRNA levels are presented in transcripts per million (TPM, y-axis). Forty-five samples from blood and neuronal lineages as evaluated by the FANTOM5 consortium  are represented in the x-axis. Detailed information on the samples included in this comparison is presented in Additional file 8.