PDCD4 and myocardial infarction: Knockout mice lacking miRNA-181a exhibit exacerbated heart function (LVEF) and fibrosis post-MI compared with control mice168, whereas mice overexpressing miRNA-181a show significantly reduced apoptosis, smaller infarct size and relatively higher LVEF, probably through suppression of proapoptotic programmed cell death protein 4 (PDCD4)169.