developed Hf–DBP–Fe, with catalase‐like activity, to decompose elevated levels of H2O2 in hypoxic tumors to generate oxygen and hydroxyl radicals (Figure5a–d).[136] The generated oxygen attenuates hypoxia to enable RDT upon X‐ray irradiation and fixes DNA damage while hydroxyl radical inflicts direct damage to tumor cells to afford CDT. Here, CAT is linked to neoplasm.