Therefore, the various structural and functional alterations of mutated ABCC6 presumably all result in the loss of physiological function, which provides a reasonable explanation for the observed lack of phenotype–genotype correlation in PXE (Le Saux et al., 2001; Chassaing et al., 2005; Pfendner et al., 2007). The gene discussed is ABCC6; the disease is pseudoxanthoma elasticum (inherited or acquired).