KDR and congenital bilateral aplasia of vas deferens from CFTR mutation: Finally, in contrast to the negligible angiogenic activity present in healthy valves, angiogenesis and the expression of vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR-2, or KDR) are all significantly upregulated in human CAVD explants when compared to healthy controls [16], [22], [23].