APOE ε2/εX was related to lower odds of amyloid pathology (CERAD: OR = 0.45, 95% CI = 0.28 to 0.72, p = 0.001 and Thal: OR = 0.39, 95% CI = 0.25 to 0.58, p < 0.001) and AD diagnosis for the whole sample (OR = 0.38, 95% CI = 0.20 to 0.74, p = 0.005) and was also protective against neurofibrillary accumulation among participants with dementia (OR = 0.19, 95% CI = 0.09 to 040, p = 0.03). The gene discussed is APOE; the disease is Alzheimer disease.