ABCC6 and pseudoxanthoma elasticum (inherited or acquired): Despite marked structural resemblance with other ABC transporters, ABCC6 is considered the odd one out as mutations in the ABCC6 gene, by which it is encoded, cause PXE, an autosomal recessive connective tissue disease primarily characterized by mineralization and fragmentation of elastic fibers (EFs) in the extracellular matrix (ECM) [4, 7, 8].