In several types of human cancers including, among others, melanoma (45), ovarian cancer (46), non-small cell lung carcinoma (47), and hematologic malignancies such as lymphomas (48–50), recruited tumor-specific effector T cells, which acquire the definition of tumor-infiltrating lymphocytes (TILs), overexpress the exhaustion markers CTLA-4, TIM-3, LAG-3 and PD-1 (44, 51–53), which elicit immunosuppressive signaling cascades leading to T cell dysfunction. This evidence concerns the gene CTLA4 and neoplasm.