The APOE gene is the strongest genetic determinant of all‐cause dementia, especially Alzheimer's disease (AD), with the ε4 allele elevating risk and accelerating age of onset (Qian et al., 2017; Rasmussen et al., 2018; Saunders et al., 1993; Lee et al., 2018). Here, APOE is linked to Alzheimer disease.