The APOE4 allele (Liu et al., 2013; Safieh et al., 2019; Yamazaki et al., 2019; Serrano-Pozo et al., 2021) has been reported to have a prevalence of 48% in AD populations (Ward et al., 2012) and 25% in the general population (Gharbi-Meliani A et al., 2021). The gene discussed is APOE; the disease is Alzheimer disease.