H2O2 is an abundant metabolite in tumor tissues.5 Relatively high levels of H2O2 can maintain the malignant phenotype of tumors and further activate the expression of hypoxia-inducible factor-1 (HIF-1), which will aggravate hypoxia-induced tumor radioresistance.6,7 Catalytic decomposition of H2O2 should be an ideal strategy for enhanced cancer RT owing to its potency in elevating the O2 concentration in tumor tissues and relieving the tumor radioresistance. The gene discussed is HIF1A; the disease is neoplasm.