Cancer immunotherapy based on immune checkpoint inhibitors (ICI), such as antibody-mediated interventions targeting cytotoxic T lymphocyte antigen-4 (CTLA-4), programmed death receptor-1 (PD-1) on T lymphocytes, and the principal ligand (PD-L1), has recently caught much attention in the field of cancer therapy for its high efficiency for reversing the tumor-induced immunosuppression and yielding a durable clinical response for a wide range of tumor types. This evidence concerns the gene CTLA4 and neoplasm.