To generate a PD1-PDL1 immunosuppressive CAR T treatment model of GBM in vivo, we used the human GBM xenograft D270 with endogenous EGFRvIII expression, and demonstrated in vitro upregulation of PDL1 upon exposure to IFNγ (Supplementary Figure S4A). Here, PDCD1 is linked to glioblastoma.