RNA works by decreasing expression of mRNA, either by repression of translation or by increased degradation of mRNA.
RNA interference is important in cell proliferation, differentiation and apoptosis. Interference RNA is controlled mainly by noncoding microRNA, which arise from longer genomically encoded nuclear transcripts from the nucleus, than transported to the cytoplasm. Endonuclease break down the DNA into smaller double stranded micro RNA's. A single stranded RNA associates with a cytosolic protein complex forms a RNA induced silencing complex (RISC). RISC could be used in therapy by targeting some cells that are overproduced.