IFNB1 and infection: Furthermore, the levels of viral load, IFN-dependent and inflammatory cytokines (IFN-β, IFN-γ, TNF-α, and IL-6) mRNA were assessed in the brain tissue of mice at 7 days post infection, also revealing a diminished pathogenicity of GETV-K648A and GETV-R649A (Fig. 11F-J).