Abstract: Programmed death1 (PD1) and its ligand 1 (PDL1) play critical roles in the identification and elimination of tumor cells evading the host′s immune system. Tumor model in mice which is given antiPDL1 monoclonal antibody shows obviously host antitumor response. Currently, immunotherapy drugs of PD1/PDL1 signaling pathways receive good effects in a variety of tumors failure of the traditional method, and with less adverse reaction, which provide valuable clinical experiences in advanced tumor immunotherapy.

Key words: Neoplasms, Immunotherapy, Programmed death ligand 1, Checkpoint inhibitors