CXCR4 and breast cancer: Helbig and colleagues has demonstrated that NF-kappaB promoted the motility of breast cancer cells by transcriptionally up-regulating the expression of CXCR4 [38]; furthermore, aberrant activation of NF-κB signaling regulates multiple genes expression, including VEGF and IL-8, which are important for lung tumorigenesis via induction of angiogenesis [39].