Fatty acid-binding protein 2 (FABP2), is also known as Fatty acid-binding protein, intestinal (FABPI), Intestinal-type fatty acid-binding protein (I-FABP). FABP2 belongs to the calycin superfamily and Fatty-acid binding protein (FABP) family. FABP2 / FABPI is expressed in the small intestine and at much lower levels in the large intestine and is highest expressed in the jejunum. FABP are thought to play a role in the intracellular transport of long-chain fatty acids and their acyl-CoA esters. FABP2 is probably involved in triglyceride-rich lipoprotein synthesis. FABP2 binds saturated long-chain fatty acids with a high affinity, but binds with a lower affinity to unsaturated long-chain fatty acids. FABP2 may also help maintain energy homeostasis by functioning as a lipid sensor.