NOS2 and infection: Our RT-qPCR data revealed a downregulation of mRNA expression of proinflammatory cytokines upon IDV infection, which were confirmed by ELISA for IL-1β and Griess test for iNOS, suggesting that this virus could negatively regulate the NF-κB pathway in the first days of infection, a mechanism that is commonly exploited by several viruses to evade the immune response (46).