Pioneering studies by Pakinski and Ameli on hypercholesterolemic rabbits showed the atheroprotective effect of immunization with modified LDL; this, in turn, fueled the use of ApoB peptides, that are specifically MHC II restricted, to trigger a CD4+ T cell response (132) and Treg increase (131), as a vaccination strategy in experimental atherosclerosis (132–135). This evidence concerns the gene CD4 and atherosclerosis.