CAT and neoplasm: Song Wu et al. combined meso-tetra(4-carboxyphenyl) porphyrin (TCPP)-conjugated peroxidase (CAT) with fluorinated CS (FCS) to form TCPP-CAT/FCS nanoparticles (NPs) (Figure 2b), which synchronously achieves noninvasive excitation of PS in orthotropic bladder and tumor hypoxia amelioration triggered by the O2 production of tumoral endogenous H2O2 catalase, significantly enhancing the efficiency of sonodynamic therapy [38].