Studies showed that some TEXs carry metalloproteinases like MMP2, MMP9, MT1-MMP, their inductor EMMPRIN (extracellular matrix metalloprotease inducer), or inactive zymogenes as well as urokinase-type plasminogen activator (uPA), which activates zymogenes, and finally, Cathepsin β, which is activated at low pH, characteristic for the tumor environment. The gene discussed is PLAU; the disease is neoplasm.