IDH1 and oligodendroglioma: However, as glioblastomas are the most common adult primary malignant brain tumor, they typically make up a large portion of the dataset, and smaller subgroups usually had a worse diagnostic performance (e.g., only 38.5% of oligodendroglioma and 62.9% of IDH-mutated astrocytoma were correctly identified compared to 90.6% of IDH-wild-type glioblastoma in [19]).