CCR4 and familial hypercholesterolemia: Taken together, these data demonstrate that CCR4 expression on Tregs plays a critical role in regulating Th1 cell responses in lymphoid tissues and may mediate Treg migration to the atherosclerotic aorta under hypercholesterolemia, which may cooperatively contribute to the reduction in early atherosclerosis by efficiently mitigating aortic inflammatory immune responses.