The ABCC6-transported substrate or substrates, which modulate arterial calcification and other phenotypic changes of PXE, are not known, and hepatic abnormalities that have effects on calcification-regulating plasma proteins such as fetuin have been suggested to at least partially mediate the pathogenesis of PXE (Hendig et al., 2006). The gene discussed is ABCC6; the disease is pseudoxanthoma elasticum (inherited or acquired).