MMP2 and neoplasm: The results demonstrated that MMP2 expression was significantly enhanced in tumor tissues (Fig. 3) and that Ad-p53 infusion therapy could partially alleviate the MMP2 expression level; although no statistically significant difference in MMP2 expression was demonstrated in the Ad-p53 group compared with the control group (P>0.05), the expression level of MMP2 in the p53+US group was significantly reduced compared with the control group (P<0.05).