In an animal model of hypercholesterolemia, a rise in Treg in atherosclerotic plaque has been observed with a concomitant lower number of Teff [97]; moreover, a depletion of CD4+ T cells may accelerate atherosclerosis in mice [98], promoting the concept of an initial atheroprotective role played by CD4+ T cells. The gene discussed is CD4; the disease is familial hypercholesterolemia.