PTGS2 and neoplasm: MT1-MMP controls a variety of signaling pathways and cell functions, including necrosis/apoptosis [4], NF-κB-mediated cyclooxygenase-2 (COX-2) expression [5,6], hypoxia-inducible factor-1 alpha (HIF-1α)-mediated response of tumor cells to hypoxia [7], and vascular smooth muscle cell differentiation [8,9].