Normal role of Micro RNA is

MicroRNA (abbreted miRNA) is a small non-coding RNA molecule (containing about 22 nucleotides) found in plants, animals, and some viruses, that functions in RNA silencing and post-transcriptional regulation of gene expression.miRNAs (microRNAs) are sho non-coding RNAs that regulate gene expression post-transcriptionally. They generally bind to the 3&;-UTR (untranslated region) of their target mRNAs and repress protein production by destabilizing the mRNA and translational silencing.