Hypoxia-induced NF-κB also up-regulates cyclooxygenase-2 (COX-2) and consequently the expression of some essential cell surface and cytoskeletal proteins required for tumor invasion, including matrix metalloproteinase-2 (MMP-2) and urokinase-type plasminogen activator (uPA) [23,50]. This evidence concerns the gene PLAU and neoplasm.