PDCD1 and neoplasm: Multiple cell membranes can be modified, for instance, tumour membrane, immune membrane, erythrocyte membrane, and bacterial membrane.299 Engineered cellular nanovesicles (NVs) which present PD-1 receptors on the cell membrane are used earlier to activate anti-tumour immunity through PD-1/PD-1 pathways.300 PD-1-MM@PLGA/RAPA is a kind of modified nanomaterial that consist of PD-1 over-expressed macrophage membrane.