CXCL12 and posterior cortical atrophy: In addition to promoting tumor cell proliferation, CAFs also stimulate tumor cell migration, at least in part via their secretion of chemotaxins (e.g., CXCL12) and matrix metalloproteinases.2 We therefore analyzed PCa cell migration using stromal CM as chemoattractant harvested from fibroblasts activated with TGFβ1 (or bFGF control) in the presence or absence of GKT137831.