For example, the increase in luminal diameter to 10−4 M acetylcholine was 26 ± 11% and 67 ± 9.7% (p < 0.01) in ApoE−/− and wild-type mice, respectively, indicative of endothelial dysfunction in the ApoE−/− mouse aorta (Figure 1C). This evidence concerns the gene APOE and endothelial dysfunction.