GRIA4 and age-related macular degeneration: We then interrogated cg18934822 (SKI), cg22508626 (GTF2H4), cg26347887 (EIF2AK3), cg01560972 (RIC3), cg18486102 (FAIM2), and cg03243226 (GRIA4) in technical (n = 38) and biological (n = 17) validation sets from human RPE samples to quantify mean methylation differences between AMD and normal RPE cells (Additional file 1: Table S2 and S5).