MET and prostate intraepithelial neoplasia: Regarding carcinogenesis, two interesting phenomena were reported in mouse models: 1) conditional MET overexpression in prostatic luminal cells revealed development of PIN by administration of HGF, however, the conditional transgenic mouse did not produce PC [54] and 2) Conditional overexpression of hepsin in prostate epithelium revealed disruption of basement membrane in vivo [55].