On the other hand, as previously reported29, 30, mutations in the tumour suppressor tp53 often co-occur with IDH1/2 mutations in low-grade glioma (P<0.0001; Fisher's exact test) and glioblastoma multiforme (P<0.00001; Fisher's exact test) (Fig. 1a). This evidence concerns the gene IDH1 and glioblastoma.