After intravenous injection, EXO@CAT NVs effectively accumulated in parental breast cancer tissues, where the Cat within the EXO@CAT NVs catalyzed the production of O2 from H2O2 in TME through the specific chemical catalysis between Cat and H2O2, thereby facilitating the active penetration of EXO@CAT NVs into the interior of the tumor. The gene discussed is CAT; the disease is neoplasm.