CD4 and neoplasm: These data argue that in the mGITRL-FP-treated mice, at the time of the priming vaccination, the tumor microenvironment was more immuno-permissive by virtue of reduced numbers of (a) CD4+FoxP3+ (Figure 4E) and (b) proliferative CD4+FoxP3- and CD8+ T cells (Figure 4F and 4G).