Fatty acid-binding protein, liver, also known as Fatty acid-binding protein 1, Liver-type fatty acid-binding protein, FABP1 and FABPL,is a cytoplasm protein which belongs to the calycin superfamily and Fatty-acid binding protein (FABP) family. Fatty acid binding proteins are a family of small, highly conserved, cytoplasmic proteins that bind long-chain fatty acids and other hydrophobic ligands. FABP1 and FABP6 (the ileal fatty acid binding protein) are also able to bind bile acids. It is thought that FABPs roles include fatty acid uptake, transport, and metabolism. FABP1 / FABPL binds free fatty acids and their coenzyme A derivatives, bilirubin, and some other small molecules in the cytoplasm. It forms a beta-barrel structure that accommodates hydrophobic ligands in its interior. FABP1 / FABPL may be involved in intracellular lipid transport.