Fatty acid binding proteins are small cytoplasmic lipid binding proteins that are expressed in a tissue specific manner. FABPs bind free fatty acids, cholesterol, and retinoids, and are involved in intracellular lipid transport. Circulating FABP levels are used as indicators of tissue damage. Some FABP polymorphisms have been associated with disorders of lipid metabolism and the development of atherosclerosis.
FABP9, also known as Testis FABP (T-FABP), testis lipid binding protein (TLBP), and PERF15, belongs to the FABP family of cytoplasmic proteins that are expressed in a tissue-specific manner. FABP binds fatty acid ligands with high-affinity and may be involved in modulating lipid metabolism. Mouse and rat FABP9 share 99% amino acid sequence identity.