CD4 and myocardial infarction: Studies have reported lower levels of circulating as well as intra lesional (local atherosclerotic lesions) Tregsin ACS patients when compared to patients with stable angina as wells as in healthy controls.91,92 A study reported that low levels of baseline circulating CD4+ Foxp3+ T cells is associated with a higher risk of future MI.93 The possible causes of the reduction in circulating Tregs number during MI include impaired output from thymus, increased apoptosis, and trafficking of peripheral Tregs to inflammatory sites.