There is convincing evidence linking matriptase to cancer in several systems (reviewed in [3], [14]), and matriptase is also a known activator of proteins with established roles during carcinogenesis such as hepatocyte growth factor (HGF) [11], urokinase-type plasminogen activator (uPA) [11] and matrix metalloproteinase 3 [32]. Here, HGF is linked to cancer.