CAT and neoplasm: Furthermore, the consumption of H2O2 will also alleviate the malignancy of tumor, thus exerting a synergistic impact on PDT treatment.[113] Tang group constructed a smart nanocomposite (UCNPs/MB@ZIF‐8@catalase) by attaching catalase onto the surface of core‐shell UCNPs/MB@ZIF‐8 to realize efficient PDT against hypoxic tumor.[102] Methylene blue (MB) served as the PS and triggered the 1O2 generation upon UCL activation, while catalase catalyzed the conversion of endogenous H2O2 to O2 and further promoted 1O2 production.