Of the more than 350 non-sensory GPCRs, many are overexpressed in prostate cancer and implicated in prostate cancer progression [15, 16]; these include receptors for chemokines (e.g., CXCR4 and CXCR7), bradykinin, lysophosphatidic acid (LPA), and endothelin 1 [17–24]. This evidence concerns the gene CXCR4 and prostate cancer.