HPN and neoplasm: HAI-1 is a potent inhibitor of pro-HGF-activating proteases, such as HGF activator, matriptase, hepsin, TMPRSS13, and human airway trypsin-like protease (HAT) [31], and our previous study demonstrated that enhanced HGF activation is observed in tumor tissue and non-tumor mucosa of HAI-1-deficient ApcMin/+ mice [29].