Kupffer cells are fundamental to the pathogenesis of YFV and other flavivirus infections, since the deleterious effects of YFV and the antiviral response are dependent on M1 macrophages and the cytokines that activate these cells, such as TNF-α, IFN-α, and IFN-γ [18,29,30]. Here, IFNG is linked to Flavivirus Infections.