CD4 and central nervous system cancer: A study by Jahan and colleagues assessed the efficacy of an anti-OX40 agonistic monoclonal antibody that stimulates CD4+ and CD8+ T cells in combination with a vaccine approach involving subcutaneously injected GL261 mouse glioma cells that over-express GM-CSF and have been irradiated prior to administration (GVAX) against the GL261 intracranial mouse glioma model [129].