IDH1mt GBMs, strongly associated with neuronal/proneuronal subsets of GBMs [5], are nowadays classified as a part of spectrum of IDH1mt astrocytomas (Astrocytoma, IDH1-mutated, CNS WHO grade 4); we therefore analysed them in the group with other IDH1mt astrocytomas [6]. This evidence concerns the gene IDH1 and astrocytoma (excluding glioblastoma).