KLK4 may, for example, affect ECM remodeling by modulating the tumor-associated urokinase-type plasminogen activator (uPA) / urokinase-type plasminogen activator receptor (uPAR) system activity, i.e. by activation of the pro-form of uPA or cleaving its receptor uPAR [42]. This evidence concerns the gene PLAU and neoplasm.