Previous studies have established that isocitrate dehydrogenase (IDH) mutation was a strong predictor associated with long-term survival of patients with GBM (8, 9), which has led the neuropathologists to reclassify GBM into two molecular subtypes: IDH-wildtype (IDH-wt) GBM and IDH-mutant (IDH-mut) GBM (10). The gene discussed is IDH1; the disease is glioblastoma.