To address checkpoints, we administered IL-15 in combination with antibodies to PD-L1 and cytotoxic lymphocyte antigen-4 (CTLA-4) in the CT26 and MC38 colon carcinoma and TRAMP-C2 prostatic cancer syngeneic tumor models (2, 69, 70). The gene discussed is CTLA4; the disease is neoplasm.