We examined this induction under 2 different culture conditions for (a) enriching glioma stem cells (GSCs) grown in a serum-free neural stem cell medium supplemented with EGF and βFGF (termed neutrosphere condition [NSC]), and (b) bulk tumor cells grown in 10% FBS in DMEM medium (termed differentiation condition, or FBS) (29) (Supplemental Figure 11B). This evidence concerns the gene EGF and glioma.