Many Studies demonstrated that CXCR4/CXCL12 is not only critical molecular determinant for events including maintaining embryo development, mediating immune and inflammatory reactions, the modulation of hematopoietic system, but also plays an important role in stimulating the metastatic process of many different neoplasm, where CXCR4 is able to activate a plethora of phenomena such as chemotaxis, invasion, angiogenesis and proliferation [26], [27]. The gene discussed is CXCL12; the disease is neoplasm.