SLC2A1 and glioblastoma: We found significantly enhanced expression of caveolin-1 protein in hypoxic regions of glioblastoma patient tumours (Fig. 3c), as determined by co-staining for the well-established hypoxia marker glucose transporter-1 (Glut-1)26 as well as increased levels of caveolin-1 in hypoxic as compared with normoxic HeLa and U87-MG cells in vitro, as shown by immunoblotting (Fig. 3d,e).