MAVS and infection: In most cell types, RIG-I (retinoic acid inducible gene I) and MDA-5 (melanoma differentiation-associated gene 5) are thought to be the primary receptors that transduce signals using a common intermediary protein called MAVS (mitochondrial antiviral signaling; also known as IPS-1/VISA/Cardif) to stimulate IFN-α/β production in response to infections by RNA viruses [3], [4], [5], [6].