CD4 and neoplasm: Previous study showed that Treg cell, which has a strong immunosuppressive function in tumor microenvironment, could regulate phosphoantigen-induced proliferation of Vγ2Vδ2 T cell ex vivo, but did not suppress the cytokine production or cytotoxic effector functions of Vγ2Vδ2 T cell (47).However, phosphoantigen+IL2-expanded Vγ2Vδ2 T cells could antagonize the expansion and functions of CD4+CD25+ regulatory T cells both in vivo and in vitro (48), and even overcome TGFβ immunosuppressive functions (49).