Recurrent GBM: resection and autopsy material, post bevacizumab. (A, B) Recurrent GBM resection material, obtained 6 weeks after last infusion of bevacizumab. Tumour cells co-opt pre-existent vessels with relatively intact BBB (arrows). (A) H&E staining 20×. (B) Glut-1, BBB marker, 20×. (C, D) Recurrent GBM: autopsy was performed 10 weeks after the last infusion of bevacizumab. Near tumour sample shows tumour cells invading along white matter tracks. (C) H&E 20×. (D) Glut-1 BBB marker, 10×.