CD274 and glioblastoma: Given that αGITR antibodies are currently being evaluated in a number of clinical trials (NCT04021043, NCT02740270, NCT02628574, NCT02598960, and NCT04225039), our study provides mechanistic insights and compelling preclinical data in support of testing the combination of αGITR with αPD1/PDL1—with or without the SoC therapy—in GBM patients with a high intratumoral accumulation of Treg cells.