These findings were consistent with studies completed in rhesus macaques, which similarly showed upregulation of tumor necrosis factor α (TNFα), IL-6, and IL-8 in response to experimentally induced H5N1 infection, along with an increase in the antiviral interferons (IFNs), findings which correlate to the severe fever symptoms observed in the macaques at the peak of the fever response at day six post-infection (78). This evidence concerns the gene CXCL8 and infection.