Since 2016, grade II diffuse and grade II anasplatic astrocytoma have been divided into mutated and wild-type IDH1/2 even if the great majority falls into IDHmut; astrocytomas, grade II oligodendroglioma are IDHmut and 1p/19q codeleted while GBMs are most often represented by GBM IDHwt (90% of cases) (Louis et al., 2016). The gene discussed is IDH1; the disease is oligodendroglioma.