CD274 and neoplasm: Immune checkpoints among these membrane proteins have been a hot spot in nearly a decade, and drugs targeting PD-1 and PD-L1 are under way in antitumor immunotherapy, as shown in the Table 1, the small molecule drugs reduce the degradation by reducing endocytosis and ubiquitination of PD-L1, thus increasing the expression of PD-L1 on tumor cell surface and with the PD-L1 monoclonal antibody targeting receptor-ligand interaction, improving the survival time of tumor patients.