MMP9 and neoplasm: One prominent direct transcriptional target of NFκB is mmp9 (Rhee et al., 2007), a matrix-metalloprotease with collagenase activity that destabilizes basement membranes and connective tissue, thereby facilitating tumor progression and metastasis (Kessenbrock and Werb, 2010; Kang et al., 2011; Dilly et al., 2013).