ApoE was initially recognized for its importance in lipoprotein metabolism and cardiovascular disease because dysfunction of ApoE protein results in familial dysbetalipoproteinemia (type III hyperlipoproteinemia), which often leads to atherosclerosis (Eichner et al., 2002; Georgiadou et al., 2011; Ghiselli et al., 1981). Here, APOE is linked to hyperlipoproteinemia type 3.