miRNA: Biogenesis, functions, gene targets, prediction tools and databases - A review

miRNAs (microRNAs) are a class of small non-coding RNAs that has roles in the silence of gene expression as they complement to their targets. Evidences are relevant enough to show that they are key regulators for various functions including development as well as diseases like cancer. The biogenesis of microRNA is a complicated process. They tend to target genes for their functions. The review basically provides information about biogenesis of miRNAs with their functions and human diseases. It includes information about their target genes and related prediction tools. It also includes briefly explained available databases.