As tumours are characterized by altered tissue-level and cellular mechanics, including ECM remodelling and stiffening, and a stiffened ECM can compromise blood vessel integrity to induce hypoxia and activate HIF1α (refs 8–10), we investigated the interplay between IDH1 mutation status, ECM mechanics, HIF1α signalling and GBM aggression. Here, IDH1 is linked to glioblastoma.