IDH1 and central nervous system cancer: In comparison to IDH-mutant HGG, GBM tumors are characterized by greater intratumoral heterogeneity, the extent correlating with survival,18 resulting in a mixture of each cell state within the tumor.13,14,18 Upon recurrence, there is a shift toward the mesenchymal lineage likely induced by immune cells and interferon signaling.19–21 The immense plasticity of glioma tumor cells allows them to reprogram and evade treatment, contributing to the poor survival of patients.22