Knowing SP plays vital roles in neuroinflammatory pathways and that drug candidates are available that inhibit the neuorikinin-1 receptor (NK1R) and substance P (SP) signaling, we studied the role of SP in WNV infection by characterizing the levels of SP over the course of infection and evaluating the therapeutic effects of an NK1R inhibitor in a pilot study. This evidence concerns the gene TACR1 and infection.