||Fatty acid binding protein 4 (Adipocyte-FABP, aP2, FABP4) is one of nine known cytosolic fatty acid binding proteins ranging in size from 14-15 kDa containing 127-132 amino acids. FABP4 is highly expressed in adipocytes and is regulated by peroxisome-proliferator-activated receptor-γ (PPARγ) agonists, insulin and fatty acids. Recent studies using FABP4 gene deletion in mice indicate a dominant role for FABP4 in several chronic metabolic diseases. Therefore, inhibiting the function of FABP4 is a potential mechanism for the treatment of metabolic diseases like diabetes and atherosclerosis. The FABP4 Ligand Binding Assay Kit provides a simple, reproducible, and sensitive tool for the identification of FABP4 ligands. The assay makes use of a Detection Reagent that exhibits increased fluorescence at 500 nm when bound to FABP4. Any strong ligand and/or inhibitor of FABP4 will displace the Detection Reagent thereby reducing the fluorescence. FABP4 is provided in high purity and in sufficient quantity for 100 tests.