DKK1 and prostate cancer: The ability of BMPs and Wnts as mediators to regulate osteoblastic activity in prostate cancer bone metastases have been evaluated by Dai et al. Administration of Wnt3a and Wnt5a, or knockdown of DKK-1 (a Wnt inhibitor), induced BMP-4 and BMP-6 expressions and promoted activation in prostate cancer cells.