This deduction is consistent with our previous study15 in which propranolol reduced VEGF and MMP-2 production, since VEGF and MMP-2 have important roles in tumor progression and metastasis.32,33 Also the important role of some pro-inflammatory cytokines in tumorigenesis has been shown.34 Thus the anti-tumor effects of propranolol in some cancers pronounced by other investigators may be in part due to its inhibitory effects on certain pro-inflammatory cytokines. Here, MMP2 is linked to cancer.