Interestingly, overexpression of miR‐21 via plasmid or adenovirus‐mediated gene transfer could protect against I/R‐induced cardiac cell death and decrease the myocardial infarct size, which may be mediated, at least in part, by its target genes, programmed cell death 4 (PDCD4) or phosphatase and tensin homology deleted from chromosome 10 (PTEN) 15, 16, 18. This evidence concerns the gene PDCD4 and myocardial infarction.