CXCR4 and cancer: Concomitan high expression of CXCR4 and VEGF has beenobserved in colorectal [74, 75], breast [38], and ovarian [34] cancers, as wellas in glioma [140] and osteosarcoma [91], in each of which it has been linkedto increased angiogenesis, invasion, and/or metastasis.