CXCL12 and prostate cancer: It has been found that activation of epidermal growth factor receptor, sonic hedgehog, Wnt/β-catenin, and stromal cell-derived factor-1 (SDF-1)/CXC chemokine receptor 4 (CXCR4) occurs during prostate-cancer progression from locally invasive to metastatic and castration-resistant prostate cancer2.