This is particularly the case for glioblastoma, where several classifications have been defined: on the one hand, the World Health Organization (WHO) classification which distinguishes between IDH-wildtype and IDH-mutant glioblastomas [2–4] and, on the other, the Verhaak classification [5], consisting of 4 subtypes depending on mutations and molecular profile of various cancer-related genes. Here, IDH1 is linked to glioblastoma.