For example, the ɛ4 allele of the apolipoprotein E gene (APOE) confers a greater risk of Alzheimer’s disease in females compared with males at ages 65–75 years.19 In line with this, several studies found significant interactions between sex and APOE ɛ4 in CSF and tau-PET biomarkers, brain hypometabolism [18F-fludeoxyglucose positron emission tomography (FDG-PET)] and atrophy, with females showing significantly greater pathological biomarker values at similar clinical stages.14,20‐23. This evidence concerns the gene APOE and early-onset autosomal dominant Alzheimer disease.