IDH mutations are commonly found in diffuse lower-grade astrocytomas and oligodendrogliomas, and they are linked to a significantly better prognosis compared to diffuse IDH-wildtype gliomas, which often resemble IDH-wildtype glioblastomas. The term "diffuse glioma" is used when the tumor cells infiltrate the surrounding brain tissue extensively, making complete surgical resection challenging and often requiring additional treatment modalities such as radiation and chemotherapy. This evidence concerns the gene IDH1 and oligodendroglioma.