CD8A and neoplasm: HSV-1 expressing murine IL-12 in substitution of γ134.5 (M002) has been compared with other strains of HSV-1 such as R3659 and G207 in the intracranial 4C8 glioma mouse model, demonstrating an increase in animal survival, a higher tumor infiltration of CD4+, CD8+, and natural killer (NK) cells, and a longer persistence of virus titers inside the tumor [37].