FABP-6 is a cytosolic protein that binds bile acids with a high affinity. In the small intestine, its expression is restricted to the ileum where it is involved in the enterohepatic circulation of bile acids. Alternate transcription promoters generate two transcript variants, encoding a 128 aa and a 177 aa residue protein. Human FABP6 isoform 2 contains 128 amino acid residues and is believed to be acetylated on Ala2.