Tumor-associated hypoxia is known to upregulate hypoxia inducible factor 1-α (HIF1-α), transcribe stromal cell-derived factor 1α (SDF-1α), and promote secretion of proangiogenic factors to recruit CXCR4+ bone marrow-derived cells (BMDCs) in the tumor milieu7–10. This evidence concerns the gene CXCR4 and neoplasm.