PDCD1 and central nervous system cancer: A notable benefit of combining oncolytic virotherapy and ICI came from preclinical studies in which one tested: measles virus and anti-PD-1 antibody; vesicular stomatitis virus (VSV) and anti-PD-1 antibody; and adenovirus Delta-24-RGDOX (expressing the immune co-stimulatory OX40 ligand) and anti-PD-L1 antibody, as well as reovirus and anti-PD-1 antibody, which all demonstrated therapeutic benefits against the GL261 glioma model [82].