MMP2 and neoplasm: When it reached tumor tissue with over‐expression of MMP‐2, the sensitive peptide GPLGIAGQ was cleaved by MMP‐2 response, then PEG was removed to leave the micelles with positive charges, thereby increasing the uptake of siRNA by tumor cells, enhancing the ability to escape from endosomes and promoting anti‐tumor efficacy (Figure 9A).