PDCD1 and cancer: Programmed cell death ligand-1 (PD-L1), the target of atezolizumab, durvalumab and others acts on the programmed cell death receptor -1, (PDCD1 or PD-1), the target of nivolumab, pembrolizumab and others, on T cells and induces T cell exhaustion, preventing the T cell from mounting an immune response against the cancer.