In order to test the robustness of the results in the meta-analyses, we perform a series of subgroup meta-analyses by excluding each study in turn, and the results showed that there was a significant association between the 2 SNPs (A2M V1001I, ABCA2 rs908832) with AD (P<0.05), except for the exclusion of Depbylu's study (A2M V1001I) and the Mace's study (ABCA2 rs908832) (Table S1). This evidence concerns the gene ABCA2 and Alzheimer disease.