MMP2 and central nervous system cancer: Some SynB3‐PVGLIG‐PTX is hydrolyzed by MMP‐2 in the extracellular matrix of glioma cells, and the released PTX plays an antitumor role in the tumor microenvironment, while other SynB3‐PVGLIG‐PTX molecules can also enter glioma cells and be hydrolyzed by MMP‐2 to release PTX.