Consistent with these results, the CFUs isolated from spleen and liver of C57BL/6 and IFN-βfloxβ-luc/floxβ-luc mice did not differ significantly, while IFN-βfloxβ-luc/floxβ-luc x LysMcre and IFN-β−/− mice showed strongly reduced bacterial numbers in the organs 24 hours after infection (Fig. 6B). This evidence concerns the gene IFNB1 and infection.