CD4 and atherosclerosis: Th17 and Treg are two subpopulations of CD4+ T lymphocytes and the Th17/Treg functional imbalance may be important in the pathogenesis of plaque destabilization and the onset of ACS.2, 3 Early and intensive statin treatment is an efficient intervention to reduce hard cardiovascular events after ACS.4 Studies showed that statins have immunomodulatory property and the effect of statins on atherosclerosis depends in part on the immunomodulatory mechanism.5, 6 However, the mechanisms of Th17/Treg imbalance in ACS patients and the effect of statins on it are still unclear.