Activated MMP‐2 is mainly located in the extracellular matrix, but there is some MMP‐2 present within cells that is activated by prooxidants to perform enzymatic hydrolysis.[46] It has also been reported that MMP‐2 is localized in the cytoplasm of human glioma cells.[47] Accordingly, we detected the content of released PTX in the normal brain tissue and tumor using the method of HPLC/MS after the administration of SynB3‐PVGLIG‐PTX. Here, MMP2 is linked to central nervous system cancer.