Based on this conception, combinations of anti-PD-1/PD-L1 mAbs with chemotherapies, targeted therapies, or CTLA4 blockade have been tested clinically and some regimes become the standard of care for several cancer types including metastatic melanoma, kidney, lung, head and neck, triple negative breast (TNB), and liver cancers. Here, PDCD1 is linked to metastatic melanoma.