CXCL2 and infection: Here, we found that, similar to mosquito biting, saliva alone in the absence of virus induced the expression of proinflammatory genes cxcl2, il1b, and ccl2, while prototypic antiviral type I interferon (IFN)-stimulated genes (isg15 and ccl5) whose expression correlates with host resistance to infection (32) were not altered (SI Appendix, Fig. S1D).