Tumor and immune microenvironments can be remodeled with EV–siRNA: M1 macrophage–derived exosomes carrying siSIRPα repolarize M2 macrophages and, with anti-PD-L1, enhance phagocytosis and suppress metastatic traits [73]; M1 EVs delivering CX3CR1 siRNA inhibit PDAC proliferation and migration and suppress tumors in vivo [74]. The gene discussed is CD274; the disease is neoplasm.