APOA1 and atherosclerosis: In advanced atherosclerotic plaques of apoE−/− mice, every other day injections of native human apoA-I over only 1 week led to atherosclerosis regression, as demonstrated by significant decreases in plaque lipid content, macrophage number, and an increase in collagen content; moreover, apoA1 injections led to a significant reduction in the plaques of inflammatory M1 and an increase in anti-inflammatory M2 macrophage markers, mannose receptor 1 and arginase 1 (73).