Thus, to test the hypothesis that the elimination of regulatory signals by immune checkpoint blockade have an enhanced therapeutic effect with anti-tumor antibodies, we treated C57BL/6 mice bearing subcutaneous B16 tumors with TA99 mAb in combination with anti-immune checkpoint mAbs including anti-PD1 (Programmed Death 1) and/or anti-CTLA4 (Cytotoxic T Lymphocyte Associated antigen 4; IgG2b depleting antibody) as indicated (Figure 3A). Here, CTLA4 is linked to neoplasm.