8‐oxo‐dG accumulation in the tumor is determined by multiple factors: 1 ROS‐induced production of 8‐oxo‐dG or 8‐oxo‐dGTP, 2 sanitization of 8‐oxo‐dGTP by MTH1, and 3 OGG1‐mediated excision of 8‐oxo‐dG from genomic DNA. The gene discussed is NUDT1; the disease is neoplasm.