PLAU and prostate cancer: Prostate cancer cells express osteoblastic factors, including endothelin-1, platelet-derived growth factor, TGF-β2, BMPs, urokinase plasminogen activator (uPA), fibroblast growth factors 1 and 2, which are all associated with proliferation of osteoblasts (Figure 1) (Mundy, 2002; Roodman, 2004).