Metabolic enzymes involved in oxidative phosphorylation (e.g., MPC elevated in poor responders) and the integrity of mitochondrial function are crucial for cancer radioresistance, while the activity of 6PGD (a component of PPP) enhances the production of NAPDH and nucleotides that promote tumor growth and radioresistance (31). The gene discussed is PGD; the disease is neoplasm.