BMS-309403 sodium is a potent, orally active, selective inhibitor of adipocyte fatty acid binding protein (FABP4, aP2), with inhibitory constants (Ki) of <2 nM for FABP4, 250 nM for FABP3, and 350 nM for FABP5. It competitively binds to the fatty-acid-binding pocket of the protein, impeding the attachment of endogenous fatty acids. This compound enhances endothelial function in apolipoprotein E-deficient mice and cultured human endothelial cells, underlining its potential therapeutic benefits [1] [2] [3].