Western blotting assay indicated that the CD133+ PCSCs sorted by MACS method exhibited increased expression of CCR5 (the binding receptor of CCL5), β-catenin and STAT3 when compared with the CD133- subpopulation, suggesting that CCL5 might promote prostate cancer metastasis by binding with CCR5 in PCSCs and then promote PCSCs self-renewal via activating the β-catenin and STAT3 pathway (Fig. 5e). This evidence concerns the gene STAT3 and prostate cancer.