These risk factors are both non-genetic, such as increasing age, and genetic, such as the E4 variant of the Apolipoprotein E (ApoE) gene, which is present in more than half of all AD patients (Corder et al., 1993; Morikawa et al., 2005; Lambert et al., 2013; Jansen et al., 2019; Reiman et al., 2020; Wightman et al., 2021). Here, APOE is linked to Alzheimer disease.