Peripheral immunomodulation over the course of tumor growth. Splenocytes were stained for extracellular CD4 and intracellular IFN-g expression. The proportion of CD4+ T cells expressing IFN-γ changes over the course of tumor development. Between the early and intermediate timepoint, the proportion of IFN-γ-producing splenic CD4+ T cells increased (5.1% vs. 8.2%, P = 0.015), and remained elevated (5.1% vs. 7.7%, P = 0.011). 13 mice were analyzed at 13 dpi (n = 4), 26 dpi (n = 4), and at 29 dpi upon exhibiting clinical tumor morbidity (n = 1) or at 40 dpi (n = 4). Differences between the means at each time point were tested using two-sided t tests with unequal variances. *, P < 0.05; **, P < 0.01, ***, P < 0.001.