CD4 and neoplasm: Besides the increased fraction of T cells in MC38 tumors post combination treatment, our data suggest an increase in anti-tumor potential of these cells as assessed by the levels of IFN-γ and granzyme B. IFN-γ is predominantly secreted by NK cells, NKT cells, CD8+ CTLs and Th1 CD4+ cells, and plays an essential role in modulating the different immune cells in favor of tumor growth inhibition (89).