MAPK14 and myocardial infarction: Intriguingly, a recent study showed that the serum level of miR-21 was upregulated in elderly patients with acute MI, and that miR-21 suppressed TNF-α-induced apoptosis in human cardiomyocytes via stimulating the activation of JNK/p38/caspase-3 signaling pathway (Wang Z.H. et al., 2017).