In tumor, CTLA-4 is upregulated on the T cells with the help of TGF-β (a suppressive cytokine secreted by the tumor cells),and during the early stage of tumorigenesis, CTLA-4 may elevate the T-cell activation threshold, thereby attenuating the antitumor response and increasing cancer susceptibility [8]. Here, CTLA4 is linked to neoplasm.