CD4 and atherosclerosis: In a mouse model of atherosclerosis, loss of MHC-II antigen presentation in hyperlipidemic ApoE deficient mice with a genetic MHCII deficiency led to a lack of splenic CD4+ T cells while double negative (DN) and CD8+ T cells increased, which ultimately led to a 2-fold increase in atherosclerosis in the aortic root.