It has been proposed that the loss of Dickkopf-3 (DKK3) expression, a secreted protein that inhibits TGF-signaling activity, either in prostate epithelial or stromal cells, could induce an increment of the expression of MMPs in PCa and the release of MMP-2 and MMP-9 [89,90]. The gene discussed is DKK3; the disease is posterior cortical atrophy.