In the past decade, immunotherapy has achieved extraordinary objective response rates for the treatment of tumors, particularly by using monoclonal antibodies (mAbs) specific to various inhibitory signaling molecules (immune checkpoints, such as programmed death-1 [PD-1] or cytotoxic T-lymphocyte antigen-4 [CTLA-4]) that are strongly upregulated by exhausted tumor-infiltrating lymphocytes5–9. This evidence concerns the gene CTLA4 and neoplasm.