CD8A and neoplasm: Forty-eight hours later, just prior to the priming vaccination, CEA.Tg mice from three treatment groups, MC32A‒tumor bearing CEA.Tg mice treated with mGITRL-FP or the control antibody and naïve CEA.Tg mice (no tumor inoculum), were examined for changes in the frequency of CD4+FoxP3+ T cells, and proliferative (i.e., Ki67+) CD4+FoxP3- and CD8+ effector T cells in the peripheral blood (Figure 4B-4D).