ARHGAP6 and Familial prostate cancer: The prostate cancer-associated SNP (rs17321482) is a QTL in an adolescent sample for the genome-wide significant age-by-sex CpG (cg23722529), mapping to ARHGAP6. Figure 3 shows a plot of methylation at cg23722529 by age, stratified by sex and genotype for rs17321482 in the discovery cohort.