Salient questions include to what extent apolipoprotein E (APOE) genotype and other factors influence the considerable phenotypic heterogeneity evident in AD,2 ranging from typical memory‐led AD to canonical atypical clinical phenotypes including visual‐/spatial,4 language‐, motor‐, or executive‐led presentations, and understanding factors associated with cognitive resilience. This evidence concerns the gene APOE and Alzheimer disease.