IFNG and cancer: It is known that IFN-γ activates the splenocyte and NK cells and not only improves their cytotoxic activity but also increases IFN-γ secretion by NK cells that play important roles in killing tumor cells by ADCC mechanism in the antitumor immunity [7, 17, 18], whereas the malignant tumors secrete high amounts of TGF-β that is associated with the advanced stage of the tumors, thereby promoting tumor growth and lessening patient survival [7, 15, 19].