IFIH1 and infection: During the early phase of infection, molecular signatures of intracellular viruses usually alarm the host pathogen recognition receptors (PRRs), including endosomal Toll-like receptors (TLRs), and cytosolic retinoic acid-inducible gene 1/helicard (RIG-1/Mda5) to activate various adaptor proteins, i.e., TRIF (Toll-IL-1 receptor domain-containing adaptor inducing IFN-β), Cardif/MAVS, and TRAFs (tumor necrosis factor-associated factors).