According to the 2021 World Health Organization classification update, it is now termed as Astrocytoma, IDH-mutant (previously called Glioblastoma, IDH mutant) and Glioblastoma, IDH-wildtype; both of which are Grade IV high-grade malignant tumors (3, 4). The gene discussed is IDH1; the disease is astrocytoma (excluding glioblastoma).