The 70 kDa peroxisomal membrane protein (PMP70) belongs to the ABCD family of peroxisomal half adenosine-triphosphate-binding cassette (ABC) transporters. ABC transporters are categorized into seven subfamilies: ABC1, MDR/TAP, MRP, ALD, OABP, GCN20, and white. PMP70 is also known as ABCD3 and is a member of the ALD subfamily. ABCD proteins function as importers of fatty acids and/or fatty acyl-CoAs into peroxisomes. PMP70 has been shown to specifically transport long-chain acyl-CoAs (LCFA-CoAs) across the peroxisomal membrane.