Resiquimod is a Toll-like receptor 7 and 8 (TLR7/TLR8) agonist that induces the upregulation of cytokines such as TNF-α, IL-6 and IFN-α. IC50 & Target: TLR7/TLR8 In Vitro: Resiquimod (R-848) induces both hapten- and allergen-specific circulating T cells, including TH2 effectors, to produce IFN-γ and even to lose the ability to produce IL-4^[2]. Resiquimod (R848) enhances PBL proliferation in a dose-dependent manner, and increases the number of BrdU-positive cells in BrdU incorporation assay. Cells treated with R848 exhibits significantly increased (3.5-fold) luciferase (a reporter of NF-κB activity) activity^[3]. In Vivo: Resiquimod (R-848) (50 μg/bird, i.m. route) significantly up-regulates the expression of IFN-α, IFN-β, IFN-γ, IL-1β, IL-4, iNOS and MHC-II genes in SPF chicken^[1].