EGFR and glioblastoma: To test whether 6PGD is phosphorylated upon EGFR activation, we generated U87 or U251 glioma cells stably expressing EGFR (U87/EGFR or U251/EGFR), and infected these cells and human primary GSC11 GBM cells with the lentivirus expressing Flag-tagged 6PGD (Flag-6PGD).