EGF and glioblastoma: In this study, after screening thirty glioblastoma patients' primary cultured cells, we found that three glioblastoma patients' tumor cells (No. 66, No. 377 and No. 1049) could form separate colonies in 10% FBS/DMEM/F-12 culture medium for 3–6 passages (Fig 1A), which in turn became floating neurospheres when switching to serum-free medium containing EGF/FGF (NSC medium).