HAO1 and neoplasm: The other is a two-dimensional (2D) PdMo bimetallene nanosheet (PMNS)36, a promising nanozyme, which not only exhibits high catalase (CAT)-like activity under neutral or acidic conditions37, promoting the catalytic decomposition of H2O2 into O2, thus potentiating the catalytic process of GOx, reducing the systemic toxicity of GOx and inducing the PA signals variation of OxyHb and DeoxyHb, but also shows peroxidase (POD)-like activity in an acidic condition4, decomposing H2O2 into highly cytotoxic hydroxyl radicals (•OH), thus augmenting the efficacy of tumor therapy.