MKI67 and neoplasm: Within the tumor microenvironment of mGITRL-FP-treated CEA.Tg mice, a significant reduction in the percentage of Ki67+/CD44+ CD4+FoxP3- T cells (Figure 4F) was found, while the frequencies of both CD4+FoxP3+ and Ki67+/CD44+ CD8+ T cells (Figure 4E and 4G) trended downward.