marginal significanceP = 0.05
When we repeated the analysis for the eight significant CpG sites in the subset sample with available genotypes ( N = 242), all eight CpG sites remained significant at P < 0.05, except for APOE cg04406254 with a marginal significance ( P = 0.05), and effect estimates for some CpGs were slightly attenuated after adjustment for APOE ε4 carrier status (Additional file 1 : Table S1).