It has been shown that the presence of IL-12 can enhance proliferation of T cells [42,43], and also facilitate interferon (IFN)-gamma production to promote Th-1-mediatedantitumor cytotoxic immunity [44] (Th1, one of the CD4+ helper T cells plays important roles in the enhancement of immunity) and the associated anti-cancer immunological response (IL-12 were reported to facilitate the development of IFN-gamma-secreting tumor-specific Th1 T cells and TILs, thereby enhancing the tumor-killing effects) [45]. Here, CD4 is linked to cancer.