The function of SPINT1 (serine peptidase inhibitor, Kunitz type 1, ENSG00000166145) is as follows. Inhibitor of HGFAC (PubMed:9045658). Inhibits serine protease activity of ST14/matriptase in vitro (PubMed:28710277). Inhibits serine protease activity of TMPRSS13, via the BPTI/Kunitz inhibitor 1 domain (PubMed:20977675). {ECO:0000269|PubMed:20977675, ECO:0000269|PubMed:28710277, ECO:0000269|PubMed:9045658}.