CD274 and neoplasm: H&E staining displayed a large number of metastatic lesions in the lungs of PBS (+), Oxa, Oxa(IV)@ZnPc, and Oxa(IV)@ZnPc@M groups, and a moderate amount of tumor cells occupied in the lungs of BMMs + anti-PD-L1, Oxa(IV)@ZnPc (+), and Oxa(IV)@ZnPc@M (+) groups.