APOE and Alzheimer disease: Research has indicated that an association exists between EEG characteristics and AD risk variants in the APOE, CLU, PICALM, IL1RAP, UNC5C, and NAV2, genes in AD and MCI patients and even in healthy adults (Jelic et al., 1997; Lehtovirta et al., 2000; Babiloni et al., 2006; Kramer et al., 2008; Ponomareva et al., 2008, 2012, 2017, 2020; Canuet et al., 2012; Lee et al., 2012; de Waal et al., 2013; Gutiérrez-de Pablo et al., 2020).