CD274 and neoplasm: Intracranial CT2A-dmEGFRvIII-Luc (A-D) and SMA560-dmEGFRvIII-Luc (E-H) tumors were analyzed for the expression of PD-1 on CD4+ and CD8+ T cells, FoxP3 on CD4+CD25+ T cells and PD-L1 on tumor cells.