Gliomas are fundamentally characterized by deranged cellular differentiation, with cell states that recapitulate the trajectory of the developing brain.6 Verhaak et al. were the first to describe a trancriptomically defined GBM classification scheme based on bulk RNA-sequencing, yielding four unique molecular subtypes: Proneural, neural, classical, and mesenchymal.18 Notably, IDH-mutant (Mut) tumors displayed exclusively proneural or neural signatures. The gene discussed is IDH1; the disease is glioblastoma.