Genetic analysis of late-onset AD has uncovered a number of single nucleotide polymorphisms (SNPs) that are associated with risk for the disease, but by far the strongest risk factor on a population level is genetic variation in the apolipoprotein E (APOE) gene (Strittmatter et al., 1993; Corder et al., 1994; Lambert et al., 2013). This evidence concerns the gene APOE and Alzheimer disease.