Nanoparticles and stem cells have proved beneficial as have microparticles, hydrogels, extracellular vesicles and shielding polymers, liposomes, and albumin as delivery systems, enabling an OV to be administered intravenously rather than topically, which can also decrease the viral virulence as the host immune system may neutralise the OV before it affects the tumour. This evidence concerns the gene ALB and neoplasm.