Out of 29 patients (21.3%) with IDH mutation, 28 patients (20.6%) had IDH1 mutations, and 1 patient (0.7%) had IDH2 mutations; they were diagnosed with CNS WHO grade 4 astrocytoma, IDH-mutant, instead of glioblastoma. This evidence concerns the gene IDH2 and astrocytoma (excluding glioblastoma).