Although reduced S1pr1 expression in LECs didn’t influence heart functions without injury, a reduction in LEC-S1pr1 expression led to a significant reduction in left ventricular ejection fraction (LVEF%) and left ventricular fractional shortening (LVFS%) after MI, compared with control WT littermates (Figures 2A–C). The gene discussed is S1PR1; the disease is myocardial infarction.