This also correlated with a TLR7-dependent alteration in chemotactic factors: where infection raised the levels of CXCL2, CCL3 and CCL11 chemokines at 4 and 7 dpi in WT mice, but these responses were blunted in TLR7 KO mice (Figure 6B), most likely accounting for the reduced airway infiltration of neutrophils, macrophages and eosinophils in TLR7 KO mice. This evidence concerns the gene CXCL2 and infection.