IFNG and infection: Finally, we tested whether L. major-infected BALB/c WT mice and IFNAR1−/− mice treated with PBS or CpG-ODN 1668 differed in their expression of IL-4 and IFN-γ mRNA at day 23 or day 24 of infection, when the lesions of CpG-ODN 1668-treated WT mice were strikingly smaller than of CpG-ODN 1668-treated IFNAR1−/− mice (Figure 6C).