CD69 and myocardial infarction: Elevation of serum cardiac damage markers, such as troponin T (TnT) and creatine kinase (CK), after MI were correlated with CD69 expression on circulating CD4+ T cells and CD4+CD25+Foxp3+ Tregs as well as with the ratios of effector T cells versus CD69+ Tregs, suggesting that CD69 expression was induced upon myocardial damage (Supplemental Table 2 and Supplemental Figure 1A).