Variation of gene feature DNAm within a CpG class. The level of DNAm was plotted as an average ß value for each gene feature in blood. Analyses were conducted within each HIL CpG class due to the large differences in DNAm that were observed between classes. Average ß values varied across probes by (A) gene location, as exemplified by intronic probes and (B) gene components, as exemplified by 5’UTR probes. 5’UTR, 5’ untranslated region; DNAm, DNA methylation; HIL, high-density CpG island (HC), intermediate-density CpG island (IC) and non-island (LC); ICshore, intermediate-density CpG island shore.