CXCL12 and neoplasm: A large body of scientific literature has reported that Stromal cell Derived Factor 1 (SDF-1, or CXCL12) and CXCR4, a chemokine and chemokine receptor pair play important roles in multiple phases of tumorigenesis, including tumor cell proliferation, survival, invasion and metastasis, and angiogenesis [1–5].