ABCG5 and posterior cortical atrophy: Using the HM450 BeadChip array, we found the promoter methylation of several genes; including SNRPN, MST1R, and ABCG5, were differentially hypermethylated in AA PCa compared to EUR PCa[39] suggesting that the differential methylation levels may influence gene expression and disease milieu in AA compared to EUR PCa.