CTLA4 and neoplasm: The scheme is shown in Figure 8B, and it was demonstrated that VSVΔ51 oncolytic viruses loaded with artificial amiRNA-4, when co-targeted with Exos carrying amiRNA-4 and PD-L1 shRNA cargoes, upregulated PD-L1 expression, sensitized tumors to CTLA4 and PD-1 immune checkpoint inhibition, enhanced death of tumor cells, and prolonged overall survival in mice (192).