The APOE-ε4 allele is associated with an increased risk of AD and has been shown to influence responses to cholinesterase inhibitors, such as donepezil and rivastigmine, as well as memantine, which is used to moderate symptoms of moderate to severe AD (Vilar and Llorens-Martin, 2021; Cacabelos, 2020; Lam et al., 2017; Serrano-Pozo et al., 2011). This evidence concerns the gene APOE and Alzheimer disease.