At this moment most immunotherapeutic approaches for the routine management of cancer are based on the (re)activation of cytotoxic T lymphocytes (CTLs) by means of monoclonal-antibodies that target immune checkpoints such as CTL associated protein 4 (CTLA-4) or programmed cell death protein 1 (PDCD1, best known as PD-1) and its ligand cluster of differentiation 274 (CD274, best known as PD-L1). Here, PDCD1 is linked to cancer.