CD4 and atherosclerosis: In line with this, 8 week treatment with IDO catabolite 3-HAA in atherosclerosis prone LDLr−/− mice has been associated to a significant reduction in lesion size, through inhibition of ox-LDL uptake by macrophages, decrease of CD4+ T-cells infiltration in atherosclerotic lesions and reduction in serum cholesterol and triglyceride levels [30].