RRM2 and glioblastoma: This was indeed the case, as shown in Supplementary Fig. 6a, both BRCA1 and RRM2 mRNA expression was markedly higher in classical GBMs (compared with mesenchymal and proneural subtype), which was reflected in the worsen survival of BRCA1 high and RRM2 high patients with classical GBM tumours (Supplementary Fig. 6b,c).