MMP9 and neoplasm: Additionally, the 5′ end of promoter region of the MMP-2 and MMP-9 gene contains a variety of regulatory sequences that binds well-characterized transcriptional units of MMP-2 and MMP-9, including nuclear factor-kappa B (NF-κB), SP-1, cAMP response element-binding protein (CREB), and activator protein (AP)-1, possibly contributing to tumor metastasis [14, 15].