IDH1 and glioblastoma: The well-established prognostic factors for GBM comprise the patients' age, neurologic function status, Karnofsky performance status (KPS), recursive partitioning analysis (RPA) group, the extent of curative resection, concurrent plus maintenance TMZ administration status, and the presence/absence of the genetic and molecular markers, like O6-methylguanine-DNA methyl-transferase (MGMT) gene promoter methylation, isocitrate dehydrogenase 1/2 (IDH-1/2) mutation, and 1p/19q codeletion [6, 7].