MMP9 and neoplasm: High NF-κB activity enhances hepatocyte growth factor (HGF) and the c-Met autocrine feedforward loop to promote tumor cell proliferation and increases the expression of prognostic factors in VS, such as matrix metalloproteinase 2 (MMP-2), MMP-9, MMP-14, COX-2, interleukin 1 (IL-1), IL-6, TNF- α (Xu et al., 2019), and signal transduction transcriptional activator 1 (STAT1) (Solinas et al., 2009), or the absolute tumor growth rate of VS (Behling et al., 2019).