In order to detect the cytotoxicity of anti-EGFRvIII CAR-T cells, anti-EGFRvIII CAR-T cells with and without the PD1CD28 chimeric molecule were co-cultured with different types of tumor cells, including WT U87 MG cells, EGFRvIII+ U87 MG cells and PD-L1 KO EGFRvIII+ U87 MG cells, at E:T ratios of 0.5:1 to 8:1(Fig 1F). Here, CD274 is linked to neoplasm.