Both intracellular and extracellular visfatin have been implicated in tumor development [24,25], with promotion of cell growth via a NF-κB/Notch1 pathway in breast cancer cells, and facilitation of metastasis and angiogenesis via PI3K/Akt, MAPK and c-Abl/STAT3 signaling pathways in human endothelial cells, macrophages and breast cancer cells [23,26,27]. Here, NAMPT is linked to breast cancer.