MicroRNAs or miRNAs are tiny RNA molecules that have only about 20 nucleotides and do not code for proteins. They regulate many important processes in cells by binding to target messenger RNAs - the instructions for protein production -, thus blocking production of the respective protein. In cancer, the production of some miRNAs is often reduced or amplified. This particularly affects miRNAs that regulate the activity of cancer-promoting genes.
More...