To further avoid host immunity to viruses or enhance tumor specific immunity induced by OVs in the future, the potential novel investigations should be focusing on the following aspects: (i) sequential harness of two different OVs, (ii) choreographed combination of OVs and antibody therapies (anti-PD-1/PDL-1, anti-CTLA-4), or cell therapies (adoptive cell transfer therapy, DC, Car-T), and (iii) improve the efficacy of administration and delivery by excellent cell carriers (MSCs, NSCs, etc.). The gene discussed is CTLA4; the disease is neoplasm.