APOE and heart disorder: We chose to study atherosclerosis because it is the primary cause of coronary artery disease which is the most common type of heart disease in men and women in the U.S. We used Apolipoprotein E−/− (ApoE−/−) mice because, like humans, they spontaneously develop atherosclerosis, whereas other murine models need additional stimuli to induce atherosclerosis development (von Scheidt et al., 2017).