PDCD1 and neoplasm: A growing number of studies support the fact that the application of programmed death receptor-1/ligand 1 (PD-1/L1) antibodies is effective in prolonging the survival of patients with cancer and can induce prolonged remission of malignant tumors.[36] The effective application of PD-1/PD-L1 pathway blockade highlights the key role played by immunosuppressive receptors in tumor progression.