One recent study indicates that the ectonucleotidase enzyme, ectonucleotide pyrophosphatase/phosphodiesterase-1 (ENPP-1), is highly expressed in CAVD and that it contributes to the elevation of extracellular Pi levels in valve interstitial cells (VICs), which are the main cellular component of the aortic valve [8]. This evidence concerns the gene ENPP1 and congenital bilateral aplasia of vas deferens from CFTR mutation.