MSR1 and atherosclerosis: In advanced atherosclerosis (i.e. after 12 weeks of feeding with a high-cholesterol diet), wild type macrophages predominated over knockout macrophages in the aortas of Msr1−/−, Cd36−/−, and Mac-Abc-DKO chimeras, but no difference was seen in blood or aortic monocytes (Fig. 2c).