CD4 and malignant colon neoplasm: It has been demonstrated previously that IFN-γ can induce activation and expansion of MDSCs in colon cancer [28], and that activated MDSCs not only inhibit effector T cell activity/proliferation but also induce immunosuppressive CD4+CD25+Foxp3+ TReg cells from CD4+CD25− T cells [6], [11], [28].