CEBPA and myocardial infarction: The immune regulatory role of epicardial signals during MI are complex: endogenous C/EBP signals are shown to mediate epicardial activation and promote neutrophil recruitment and inflammatory responses in the infarcted hearts,[51] whereas the YAP/TAZ signaling is shown to suppress post‐infarct inflammatory responses through the recruitment of Tregs.[52] In the present study, we provide evidence showing that human exogenous epicardial cells suppressed IFN‐I signaling‐mediated inflammation and promoted reparative macrophage shifts in the infarcted hearts.