GBMs are classified into primary, often arising de novo in adults and requiring IDH-wildtype, which is associated with shorter survival, showing 15 months overall survival and 7–9 months progression-free survival, and secondary, developing from lower-grade astrocytoma and requiring IDH-mutant, which is better prognosis showing 31–46 months overall survival and 11–20 months progression-free survival [18,19,20]. Here, IDH1 is linked to astrocytoma (excluding glioblastoma).