ABCC6 and pseudoxanthoma elasticum (inherited or acquired): However, the clear resemblances between the GACI and PXE phenotypes rather suggests an underlying convergence of ENPP1 and ABCC6 molecular pathways toward a common inhibition of mineralization somewhere upstream of the phenotypic manifestations, i.e., calcification because ENPP1 deficiency leads to elastic fiber alterations typical of PXE in the vasculature, the skin, and ocular tissues (Figure 2A).