Serine protease that cleaves extracellular substrates, and contributes to the proteolytic processing of growth factors, such as HGF and MST1/HGFL. Plays a role in cell growth and maintenance of cell morphology. Plays a role in the proteolytic processing of ACE2. Mediates the proteolytic cleavage of urinary UMOD that is required for UMOD polymerization. Cleavage after basic amino-acid residues, with Arg strongly preferred to Lys. Widely expressed. Present in brain, heart, kidney, liver, stomach, muscle, lung, testis, skin and eye. Not expressed in ovary and thynus. In inner ear tissues, expressed in stria vascularis, modiolus, organ of Corti and spiral ganglion. Expressed during development in embryonic stages E8.5, E9.5, E12.5 and E19. Belongs to the peptidase S1 family.