Stromal cell-derived factor-1 (SDF-1), also known as CXC motif chemokine ligand-12 (CXCL12), which binds to the CXC receptors 4 and 7, is ubiquitously expressed in almost all organs and involved in several aspects of tumor progression, including angiogenesis, metastasis, and survival (11). The gene discussed is CXCL12; the disease is neoplasm.