HPN and prostate cancer: Thus, hepsin may have a role in tumor progression, invasion, and metastasis but not in primary tumor growth, which was supported by a study in a hepsin transgenic mouse model, showing that the overexpression of hepsin in a mouse model of non-metastasizing prostate cancer had no impact on cell proliferation but caused disorganization of the basement membrane and promoted primary prostate cancer progression and metastasis to the liver, lungs, and bones [12].