IDH1 and oligodendroglioma: The combination of TERTp and IDH mutations, in particular, allows the assignment of diffuse astrocytic and oligodendroglial tumours in discrete groups with different survival rates: TERTp and IDH-mutated tumours present the longest overall survival, while patients with only TERTp-mutated tumours present the lowest survival, as shown in several reports [61,71,73,74,78,79].