CTLA4 and astrocytoma (excluding glioblastoma): TS = (ipilimumab) OR TS = (pembrolizumab) OR TS = (nivolumab) OR TS = (tremelimumab) OR TS = (immune checkpoint blockade) OR TS = (*immunotherapy) OR TS = (vaccine) OR TS = (CAR-T) OR TS = (immune checkpoint inhibitor) OR TS = (PD-1) OR TS = (PD-L1) OR TS = (CTLA-4) OR TS = (LAG-3)) AND (TS = (glioma*) OR TS = (neurolipocytoma) OR TS = (neurospongioma) OR TS = (neuroglioma*) OR TS = (glioblastoma*) OR TS = (GBM) OR TS = (gliosarcoma) OR TS = (astrocytoma)