While the aorta of a C57Bl/6 mouse prior to a high-fat diet shows no atherosclerotic changes in the vessel wall (Figure 1A), long-term high-fat diet for 22 weeks reveals a high load of large fat-rich plaques around the bifurcation in the aortic arch of the ApoE−/− mouse aorta (Figure 1B) as typically observed during atherosclerosis development in humans. The gene discussed is APOE; the disease is atherosclerosis.