CD4 and neoplasm: The fast kinetics of tumor rejection did not allow us to quantify the tumor infiltration of CD4+ and CD8+ cells in Mef2c-/- mice, but we observed higher activation (CD44high/CD62Llow) and greater IFN-γ production by CD4 and CD8 (Figures 5D, E) T cells in the tumor-draining lymph nodes and spleens of Mef2c-/- mice versus WT tumor-bearing mice.