MMP9 and neoplasm: The presented studies suggest the existence of a ‘vicious cycle’ (Figure 1) whereby Gal-8, secreted by tumor and naïve cells present in the tumor microenvironment, promotes in an autocrine and paracrine manner the secretion of chemokines, cytokines, and additional proteins (e.g. MMP9, GAS6) that support tumor growth and induce recruitment of cancer cells to the metastatic niche.