CXCR4 and cancer: The effects resulting from Sp1 knockdown are consistent with the parallel decrease in pro-oncogenic Sp-regulated genes associated with cancer cell survival (bcl-2, survivin), proliferation (EGFR, c-MET, cyclin D1), angiogenesis (VEGF and VEGFR1), inflammation (p65NFκB), and invasion (CXCR4 and MMP9) [18].