PLAU and cancer: In this milieu, cancer cell-derived IL-4, CXCL12, FGF (fibroblast growth factor), PDGF, and TAM-derived TGF-β [36], MMPs, urokinase-type plasminogen activator (uPA), and IL-6 affect ECM proteolysis, thus promoting the migration of tumor cells and the eventual release of important mediators of tumor spread [37].