The diversity of (patho)physiological observations in PXE – oxidative stress, the PXE serum factor, vitamin K deficiency, the relation with ENPP1, does not make it unthinkable that they result from aberrant transport of more then one substrate, thus influencing more than one physiological process (Le Saux et al., 2006; Pasquali-Ronchetti et al., 2006; Vanakker et al., 2010; Nitschke et al., 2011). Here, ENPP1 is linked to pseudoxanthoma elasticum (inherited or acquired).