In the case of glioma, breast cancer, and prostate cancer, HIF-1α activates pro-survival pathways such as Notch, wingless, INT-1 (WNT), and the Hedgehog pathway, which are important for CSC maintenance, which leads to radioresistance and repopulate CSCs during or after treatment [103]. The gene discussed is HIF1A; the disease is central nervous system cancer.