APOE and Alzheimer disease: APOE4 is an AD susceptibility factor and high-risk gene that can significantly lower the age of onset of AD (Genin et al., 2011; Hu et al., 2015; Liu et al., 2015; Najm et al., 2019); about 60–75% of AD patients are APOE4 gene carriers (Genin et al., 2011; Hu et al., 2015; Liu et al., 2015; Najm et al., 2019).