Whilst concentrations of MMP-9 and CCL2 were reduced upon infection, IFN-β (Fig. 5C) and CXCL10 (Fig. 5D) were induced as the infection course progressed, with significant increases over mock after 48 hpi and 72 hpi for both the USUV- and WNV-infected conditions. This evidence concerns the gene MMP9 and infection.