In line with the clinical findings, C57BL/6 IFN-β−/−, IFNAR1−/−, and WT mice exhibited similar mRNA expression levels of IFN-γ, interleukin (IL)-4, IL-12, IL-13, inducible nitric oxide synthase, and arginase 1 during the acute and late phase of the infection. This evidence concerns the gene IL4 and infection.