By inhibiting the immunosuppressive processes in several cancers (for instance, lung cancer of the non-small cell kind or metastatic melanoma), CTLA 4 and PD-1 (Cytotoxic T Lymphocyte-Associated Protein 4 and Programmed Cell Death Protein 1) enhance the immune response [14–16]. The gene discussed is PDCD1; the disease is metastatic melanoma.