TNFSF11 and posterior cortical atrophy: We found that the expression level of RANKL was significantly increased by TGF-β treatment in C4-2B and PC-3 cells (Figure 3A), suggesting that the induction of osteoclast differentiation by TGF-β was mediated through the up-regulation of RANKL and that PCa cells could produce RANKL to induce osteoclast differentiation.