CD133+ brain tumor stem cells in glioblastoma have reduced sensitivity to radiation-induced apoptosis [15],[40] and similar findings were made by Bao et al that CD133+ tumor stem cells isolated from both human glioma xenografts and primary patient glioblastoma specimens preferentially activate the DNA damage response after radiation treatment and repair radiation-induced DNA damage more effectively than CD133- bulk tumor cells [41]. The gene discussed is PROM1; the disease is glioma.