These findings indicate that co-existent IDH1R132H tempers ATRX-deficient inflammatory signaling in gliomas, further supporting the notion that mutant IDH1 confers an immunosuppressive phenotype and pointing to a pathogenically relevant immunological interplay between the defining molecular alterations of IDH-mutant astrocytomas. This evidence concerns the gene ATRX and astrocytoma (excluding glioblastoma).