MMP2 and cancer: Previous studies have shown that bufalin exerts antitumor effects through inhibition of AKT [5, 27], heat shock protein 27 (Hsp27) [28, 29], GSK3beta/beta-catenin/E-cadherin [5], NF-kB [12], and matrix metalloproteinase-2/-9 [12] signaling pathways in various cancer cells.