APOE and early-onset autosomal dominant Alzheimer disease: Since APOE has already been linked to numerous measures of age-related change and cross-sectional functioning (e.g., cognitive ability44–47/decline14,44,45,47,48, brain levels/change49, Alzheimer’s disease risk/progression50,51, BMI levels/change52,53, biomarker levels/change38,54), together these findings highlight that APOE is neither trait nor state specific.