More specifically, we show that the trout SB mucosa exhibited an upregulation of antiviral genes (RIG-I, LGP2, Mx1, IRF7, and MDA5) that are known to be essential for the production of effective antiviral responses in the mammalian type-I mucosal surfaces, such as lung, gut, and nose, particularly at early stages of infection (i.e., 4 and 7 DPI)49–51. This evidence concerns the gene IFIH1 and infection.