APOE and Alzheimer disease: In addition, polar metabolites associated with APOE region SNPs in the E2, E3, and E4 groups have been implicated in AD (Jiménez-Jiménez et al., 1998; Selley, 2003; Dobolyi et al., 2011; Gueli and Taibi, 2013; Kaddurah-Daouk et al., 2013; Wang et al., 2014; Ansoleaga et al., 2015; González-Domínguez et al., 2015; Luo et al., 2015; Syeda et al., 2018; Baumel et al., 2021) and CAD (Valkonen et al., 2001; Bäckström et al., 2003; Lewis et al., 2008; Tveitevåg Svingen et al., 2013; Bartolomaeus et al., 2019; Cappola et al., 2019).