To provide additional evidence that the CXCR4/CXCL12 signaling is important for stem-like cell maintenance and targeting of this pathway can lead to inhibition of prostate cancer progenitor growth, we tested if inactivation of the CXCR4/CXCL12 axis by a neutralizing antibody affects prostate cancer progenitors in vitro and in vivo. This evidence concerns the gene CXCL12 and Familial prostate cancer.