In TT-carriers in this study, we found that memory scores of ε4+ carriers were not worse than those of ε4 non-carriers, suggesting a protective effect of homozygosity for ABCA7 rs3764650T allele against memory impairment in AD patients that carried APOE-ε4 allele even though the TT-carriers who carried APOE-ε4 allele had a trend of lower educational level than those who were APOE-ε4 non-carriers. Here, APOE is linked to memory impairment.