Similarly, expression of several genes in the canonical IFN signaling pathway, including Ifng, Jak2, Stat1, Stat2, Socs1, Irf1, Irf9, Tap1, Ifitm1, Psmb8, Ifi35, Gas1 and Fit3 were up-regulated during infection by the mutant strain (Figure 5C). The gene discussed is IRF9; the disease is infection.