CXCL13 and posterior cortical atrophy: In PCa, serum CXCL13 levels is positively correlated with prostate specific antigen and prostatic disease; and PCa cell lines selectively express certain matrix metalloproteinases (MMPs) in response to aberrant expression of CXCL13, suggesting that migration and invasion of PCa cells is via degrading extracellular matrix (ECM) components [25, 26].