In the present study the effect of ifih1 knockout was tested on the ability to activate the IFN1 pathway and to generate CPE after infection with a collection of fish viruses belonging to different categories: positive single stranded RNA (SAV2, Nodavirus), negative single stranded RNA (SHRV, IHNV) or double stranded RNA (IPNV). The gene discussed is IFIH1; the disease is infection.