IFNG and infection: In contrast to IFN-γ, which peaks around 6 d.p.i. and is virtually undetectable after two weeks [22–24], MCSF levels continued to increase in the plasma of infected mice for two weeks post-infection (Fig 2H), a time frame coincident with the peak of myeloid expansion (Fig 1B), consistent with the hypothesis that this cytokine might support the observed proliferation of myeloid cells at later timepoints.