CD4 and glioblastoma: Since T cells contributed to D2C7-IT-mediated antitumor response (Fig. 3) and glioblastomas support an immunosuppressive microenvironment [13, 14, 18, 19], we examined the phenotype of CD4+ and CD8+ T cells and tumor cells in CT-2A-dmEGFRvIII-Luc (day 6 and end-stage), and SMA560-dmEGFRvIII-Luc (day 4 and end-stage) intracranial tumors.