Serine protease that cleaves extracellular substrates, and contributes to the proteolytic processing of growth factors, such as HGF and MST1/HGFL (PubMed:15839837, PubMed:21875933). Plays a role in cell growth and maintenance of cell morphology (PubMed:21875933, PubMed:8346233). Plays a role in the proteolytic processing of ACE2 (PubMed:24227843). Mediates the proteolytic cleavage of urinary UMOD that is required for UMOD polymerization (PubMed:26673890). {ECO:0000269|PubMed:15839837, ECO:0000269|PubMed:21875933, ECO:0000269|PubMed:24227843, ECO:0000269|PubMed:26673890, ECO:0000269|PubMed:8346233}. This is the function of HPN (hepsin, Ensembl gene identifier ENSG00000105707).