IL4 and infection: By comparison, Spn single infection as well as coinfection significantly increased serum IL-10, IL-12p70, IL-1β, IL-6, KC/GRO, and TNFα, while IFNγ concentrations were moderately, but not significantly, increased during coinfection, and IL-4 concentrations were only increased when mice were exposed to pulmonary Spn alone.