CAT and neoplasm: The treatment strategy has the following characteristics: (1) In TME, ·OH and O2·− produced from the inherent POD-like and OXD-like activities of CM@MnOx can kill tumor cells and cause the death of immunogenic cells, meanwhile, the production of oxygen from the CAT-like activities can alleviate tumor hypoxia, thereby alleviating the tumor immune suppression microenvironment.