In addition, radioresponse regulation via MGMT control in GBM, GSCs, and melanoma was associated with persistence of radiation-induced γH2AX foci and radiation-induced cell death by mitotic catastrophe, suggesting that MGMT is associated with repair of radiation-induced DNA double-strand breaks (DSBs) in GBM, GSCs, and melanoma. The gene discussed is MGMT; the disease is glioblastoma.