A particular importance focuses on overexpression of immunosuppressive checkpoints, such as cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), Programmed Death 1 (PD-1), and Programmed Death-Ligand 1 (PD-L1) within the TME, which can impair the immune system’s ability to destroy cancer cells [8,9]. This evidence concerns the gene CTLA4 and cancer.