In athymic mice bearing intracerebral U87 GBM, systemic administration of Bevacizumab, a monoclonal antibody directed at VEGF, increased spread of G47Δ-mAngio, G47Δ oHSV engineered to secrete anti-angiogenic protein murine angiostatin, as well as the anti-angiogenic effect. The gene discussed is PLG; the disease is glioblastoma.