Upon infection of RNA virus, the invaded cytosolic viral RNA is sensed by the RNA helicase RIG-I or MDA5.9,10 Binding of RIG-1 or MDA5 to viral RNA triggers its recruitment to VISA (also called MAVS), a mitochondrion-associated adapter protein.11,12 VISA then recruits the adapter protein TRAF3, the TBK1 kinase, and the transcription factor IRF3. This evidence concerns the gene IFIH1 and infection.