Disease: Defects in ABCC6 are the cause of pseudoxanthoma elasticum (PXE) [MIM:264800]. PXE is a disorder characterized by calcification of elastic fibers in skin, arteries and retina that results in dermal lesions with associated laxity and loss of elasticity, arterial insufficiency and retinal hemorrhages leading to macular degeneration. PXE is caused in the overwhelming majority of cases by homozygous or compound heterozygous mutations in the ABCC6 gene (autosomal recessive PXE). Individuals carrying heterozygous mutations express limited manifestations of the pseudoxanthoma elasticum phenotype (autosomal dominant PXE). Function: May participate directly in the active transport of drugs into subcellular organelles or influence drug distribution indirectly. Transports glutathione conjugates as leukotriene-c4 (LTC4) and N-ethylmaleimide S-glutathione (NEM-GS). Similarity: Belongs to the ABC transporter superfamily. ABCC family. Conjugate transporter (TC 3.A.1.208) subfamily. Contains 2 ABC transmembrane type-1 domains. Contains 2 ABC transporter domains. Tissue specificity: Expressed in kidney and liver. Very low expression in other tissues.