CD274 and neoplasm: In contrast, DTP-PDT alone resulted in an 81.62% reduction in primary tumor weight (p < 0.001 vs. model and α-PD-L1), but only a 35.35% reduction in distant tumor weight (p > 0.05 vs. model and α-PD-L1), highlighting that PDT has a significant therapeutic effect on irradiated primary tumors but little effect on unirradiated distant tumors.