CXCR4 and ovarian cancer: Among the downregulated genes, CXC motif chemokine receptor 4 (CXCR4) encodes a CXC chemokine receptor specific for stromal cell-derived factor-1, and the inhibition of either CXCR4 or its ligand, CXCL12, reduces tumor growth in vitro and prolongs the survival of immunocompetent mice infused with ovarian cancer cells (Darash-Yahana et al. 2004; Righi et al. 2011).