RIG-I (retinoic acid inducible gene-I) is one of cytoplasmic viral sencers which has a RNA helicase domain and it is believed to recognize virus-derived double-stranded RNA (dsRNA). It is considered that RIG-I normally exist as inactive form in cytoplasm and turns to active form when it recognizes dsRNA produced as a by-product of viral replication. And it is thought that active form of RIG-I exposes a signaling domain called CARD (caspase recruitment domain) which had been hidden by the steric hindrance and the downstream signaling is activated by interaction of the CARD with IPS-1 expressed on a mitochondria, eventually induces the activation of interferon gene. Thus, RIG-I is believed to play an important role in viral infection-induced signaling. This antibody recognizes CTD (C terminal domain) of RIG-I and is able to detect RIG-I localized in avSGs (antiviral stress granules) that are genesis-induced in virus-infected cells