IDH1 and central nervous system cancer: According to the WHO classification of central nervous system tumors and the cIMPACT-NOW update 3, IDH wild-type astrocytomas now are considered to be corresponding to CNS WHO grade 4 tumors, if one of the following alterations is confirmed: high-level EGFR amplification, the combination of whole chromosome 7 gain and 10 loss or TERT promoter mutation [12, 13].