Definition for View source for MicroRNAs (miRNAs)

1) Small RNA molecules, typically 22 nucleotides long, that silence the expression of specific mRNAs, either by inhibiting translation or by promoting the degradation of mRNAs.

2) MicroRNAs (miRNA) are an abundant class of small, non-coding RNAs (∼22 nt long), which negatively regulate gene expression at the level of [[messenger RNA]]s (mRNAs) stability and translation inhibition.