ABCC6 and Pseudoxanthoma elasticum: Using a systematic approach in a pre-genome sequence era, Struk et al. and van Soest and colleagues independently reported a significant linkage of the PXE phenotype to the chromosome 16p13.1 region [37,38], and screening of candidate genes led to the identification of disease-causing mutations in the ABCC6 gene that was then referred to as MRP6 in the old nomenclature [8,9,10].