TMPRSS4 and familial pancreatic carcinoma: Cheng et al.67 reported that HAI-1 suppresses EMT in pancreatic cancer cells by modulating both matriptase and TMPRSS4, suggesting that TMPRSS4 activity may be regulated by the endogenous inhibitor HAI-1, although further investigation is needed to determine whether HAI-1 interacts with/inhibits TMPRSS4 directly.