These results are consistent with the increased susceptibility of those with apoE4 to various environmental challenges (Raber, 2004; Liu et al., 2013) and the cognitive impairments reported in mice expressing apoE4 in neurons (Raber et al., 2000; Raber et al., 1998) or astrocytes (Van Meer et al., 2007) and on an apoE knockout background. This evidence concerns the gene APOE and Cognitive impairment.