APOE and atherosclerosis: In this study, we irradiated 3 month old age-matched ApoE null male mice, which can develop both spontaneous and diet-induced atherosclerosis (Nakashima et al., 1994; Lo Sasso et al., 2016), to assess the acute and long-term effects of simGCRsim- (50, 100, 150 cGy) and γ-IR (100, 200, 400 cGy) on LV function and structure.