We investigated whether the association between mCAs and AD varied by APOE ε4 genotype, a major genetic risk factor for AD that is associated with different phenotypic and pathological features.13 The mCA-associated risk tested in all ancestries combined appeared to be stronger among APOE ε4 non-carriers (OR = 1.16 vs 1.31 for the presence of any mCA types between APOE4 carriers and non-carriers in all ancestries; Fig. 1c and Supplementary Table 3). This evidence concerns the gene APOE and Alzheimer disease.