Purity >98%. Fatty acid binding protein 4 (FABP4) is a lipid transport protein that is also known as adipocyte FABP and aP2. In addition to adipocytes, it is also abundant in macrophages, along with FABP5, the epidermal FABP. BMS309403 is a cell-permeable, potent inhibitor of FABP4 that targets the fatty acid-binding pocket (Ki < 2 nM). It is less effective against FABP3 and FABP5 (Ki s = 250 and 350 nM, respectively). BMS309403 is orally active, reducing atherosclerosis in mice lacking apoplipoprotein E. It also protects against the development of insulin resistance associated with genetic or diet-induced obesity in mice. FABP4 dose-dependently suppresses the release of MCP-1 from macrophages.