CD4 and central nervous system cancer: The amount of intratumoral CD8+ and CD4+ T-cells per mm2 increased significantly in all treated groups in the GL261 glioma model (CD8+/mm2: CED-TMZ + GL261 vs. non-treated: p = 0.0022; CED-TMZ vs. non-treated: p = 0.0273; GL261 vs. non-treated: p = 0.022.