Extracellular proteases mediate the digestion of neighboring extracellular matrix components in initial tumor growth, allow desquamation of tumor cells into the surrounding environment, provide the basis for invasion of basement membranes in targeted metastatic organs and are required for release and activation of many growth and angiogenic factors (1,2). The TMPRSS2 gene encodes a 492 amino acid multimeric serine protease, which is mainly expressed in the mouse prostate and kidney, and is