RIGI and viral infectious disease: PRRs, such as Toll-like receptors (TLRs), the cytosolic retinoic acid-inducible gene I (RIG-I) and melanoma differentiation-associated protein 5 (MDA-5), recognize viral RNA as PAMPs (pathogen associated molecular patterns) and respond by activating signaling networks that culminate in the induction of interferons (IFNs) and establish an antiviral state, which helps to limit viral infection [1,2].