IDH1 and glioblastoma: For primary lesions (n = 15, 50%), the frontal lobe was the preferred location (Fig. 6a, left side), whilst recurrent tumours (n = 10, 90%) were enriched in the temporal lobe (Fig. 6a, right side), similar to our observations in IDH-wildtype glioblastomas with primitive neuronal components (52% located in the temporal lobe [18]).