IDH1 and glioblastoma: This new classification takes into account both the molecular and histological characteristics: it integrates the genotypic and phenotypic parameters and classifies GBMs based on their isocitrate dehydrogenase (IDH) mutation status as IDH-wild type, IDH-mutant, or as GBM with an inconclusive or unavailable IDH mutation status, such as GBM NOS (not otherwise specified) [11].