Besides the histomorphology of an infiltrating diffuse astrocytic tumor, several biomarkers are required to confirm the diagnosis of a glioblastoma: astrocytic tumors, presenting with necrosis or microvascular neoproliferation in the absence of an IDH-mutation and wildtype histone H3 status are characterized as IDH-wildtype glioblastoma, WHO grade 4 [13,14]. The gene discussed is IDH1; the disease is glioblastoma.