ENPP1 and Pseudoxanthoma elasticum: The finding that MGP and fetuin A are involved in both conditions further sustain the hypothesis that ABCC6 mutations account for a significant subset of GACI patients, and ENPP1 mutations can also be associated with PXE lesions in young children, thus reflecting two ends of a clinical spectrum of ectopic calcifications, possibly through the involvement of common physiological pathways (Nitschke et al., 2012).