POSTN and posterior cortical atrophy: Summarizing the previous results, we find that: (1) POSTN is identified in osteoblasts and preferentially expressed in the periosteum as a putative bone adhesion molecule (17, 18); (2) POSTN is a secreted matricellular protein (31); (3) POSTN was regulated by TGF-β (25); (4) POSTN is a ligand of the integrin family (19, 32); and (5) POSTN promotes EMT of PCa cells (33).