EGF and neoplasm: Human NSPCs were isolated from autopsy GM dissections, and GSCs from isocitrate dehydrogenase (IDH)-wildtype GBM surgical specimens, by fluorescence-activated cell sorting (FACS), based on their EGF ligand-binding ability (Fig. 1a, Supplementary Fig. 1); this purification strategy prospectively captures all sphere-forming and tumor-initiating EGF-bound cells in uncultured conditions17.