microRNAs: Epigenetic players in cancer and aging.

MicroRNAs (miRNAs) are endogenous, small non-coding RNA molecules that play important regulatory roles in numerous biological processes, cellular pathways and networks. They do so by targeting specific mRNAs, directly degrading them and/or preventing their translation into proteins. The impaired function of miRNAs results in aberrant gene expression that promotes abnormal cell growth and differentiation.