We compared the gene expression pattern between wild type and NAMPT-silenced human endothelial cell and a breast cancer cell line to identify genes potentially regulated by NAMPT. Two independent microarray datasets containing gene expression information for both wild type and NAMPT-silenced cells were collected from the Gene Expression Omnibus (GEO) database12: one dataset was derived from a MCF-7 breast cancer cell line (GSE13449)13 and the second dataset was from human pulmonary microvascular endothelial cells (GSE34512)14. The gene discussed is NAMPT; the disease is breast cancer.