MMP9 and pancreatic neoplasm: In addition to enhancing M2-polarization and the secretion of PGE2 by THP-1 macrophages, AsPC-1 exosomes increased the secretion of several other bioactive growth factors, chemokines and cytokines including VEGF, MCP-1, IL-6, IL-1β, MMP-9, and TNFα, all of which have been shown to contribute to pancreatic tumor growth and progression (Fig 6).