Experimental and clinical data indicate that breast cancer cells overexpress diverse GPCRs, such as lysophosphatidic acid (LPA) receptors, chemokine receptors (such as CXCR4 and CXCR7), and protease-activated receptors (PARs), and produce high levels of GPCR ligands (such as LPA and SDF1α) [3, 14–17]. This evidence concerns the gene ACKR3 and breast cancer.