Early studies revealed the importance of MT-SP1 in prostate cancer progression and indicated the existence of other serine proteases involved in the cascade. Developing selective and potent protease inhibitors is challenging due to frequent coexpression of other similar proteases. The antibody scaffold is an attractive choice for the development of highly potent and selective inhibitors. A phage-displayed antibody library was screened against a cancer- associated protease membrane-type serine protease 1 ...