Wild-type YFV-infected AB6 mice produced higher levels of serum cytokines (IFNγ, MIG, MCP-1, IL-4, IL-5, IP-10, and TNFα) more rapidly than in 17D-infected AB6 or AGB6 mice (Fig. 3), possibly associated with the severe viscerotropic disease and rapid death of the WT virus-infected animals.19 The cytokines that are more significantly upregulated in 17D-204-infected AB6 but not AGB6 mice, i.e. IL-12, MCP-1, MIG, and IP-10, are all IFN-γ-inducible, suggestive of a central role for IFN-γ in protecting AB6 mice from 17D-204 infection through cytokine induction. The gene discussed is IL4; the disease is infection.