The function of TMPRSS13 (transmembrane serine protease 13, ENSG00000137747) is as follows. Serine protease (PubMed:20977675, PubMed:28710277, PubMed:34562451). Cleaves the proform of PRSS8/prostasin to form the active protein (PubMed:34562451). Cleaves the proform of HGF to form the active protein which promotes MAPK signaling (PubMed:20977675). Promotes the formation of the stratum corneum and subsequently the epidermal barrier in embryos (By similarity). {ECO:0000250|UniProtKB:Q5U405, ECO:0000269|PubMed:20977675, ECO:0000269|PubMed:28710277, ECO:0000269|PubMed:34562451}.