A total of 259 IDH-mut tumors were identified, from which 80 tumors could be further specified as IDH-mut astrocytoma (median follow-up 6.6 years) and 93 tumors were identified as IDH-mut oligodendroglioma (median follow-up 7.5 years). Here, IDH1 is linked to astrocytoma (excluding glioblastoma).