IDH1 and glioblastoma: Through prospective genomic profiling of primary de novo IDH-wildtype glioblastomas in a large cohort of adults, we have identified a new distinct glioblastoma subtype that appears to be unique in its age at presentation, histological features, oncogenic driver events, mechanism of telomere maintenance, chromosomal copy number profiles, DNA methylation patterns, cellular composition, and clinical outcomes.