Thus, many inherited mineralization, calcium handling or calcification-related disorders have been linked to loss-of-function mutations in ENPP1, including autosomal recessive hypophosphatemic rickets type 2 (ARHR2), ossification of the posterior longitudinal ligament of the spine, generalized arterial calcification of infancy (GACI), arterial calcification due to CD73 deficiency (ACDC), and pseudoxanthoma elasticum (PXE), also referred to as Gronblad-Strandberg Syndrome (GSS) in some reports [10,11,12,13]. The gene discussed is NT5E; the disease is pseudoxanthoma elasticum (inherited or acquired).