RIG-I is a receptor found in the cytoplasm that recognizes viral RNA from replicating viruses in infected cells. Upon activation with intracellular RNA, a cascade is triggered resulting in the activation of NF-kappa-B, and the eventual induction of antiviral cytokines such as IFN-beta and RANTES. RIG-I is essential for the production of interferons in response to RNA viruses and as such play a key role in innate immunity.