CD274 and cancer: The results showed that CPPM could be safely and stably targeted to the tumor site for a long time through the EPR effect, specifically bind to PD-L1 on the tumor surface, increase the accumulation of the drug in the tumor cells, enhance the PDT to generate ROS, induce endoplasmic reticulum stress in the tumor cells, and combine with MAC to revitalize the activity of the T cells and promote the proliferation of the T cells, which would enhance the antitumor immune ability and ultimately kill cancer cells (Fig. 1B).