Utilizing a 3D co-culture model of breast cancer cells and human umbilical vein endothelial cells, we demonstrated that Sdc-1 depletion in tumor cells decreased endothelial tubule network formation and decreased the expression and secretion of vascular endothelial growth factor (VEGF) and several constituents of the tissue factor (TF) pathway [11]. The gene discussed is SDC1; the disease is breast cancer.