“…Indeed, a selective biphenyl azole inhibitor of FABP4, BMS309403, was identifi ed as binding FABP4 with nM affi nity and >100-fold selectivity against FABP5 as well as the heart isoform FABP3 ( 9 ). In a ligand displacement assay using 1,8-ANS (8-anilino-1-naphthalene-sulfonic acid) as the probe, the compound displays inhibition constant ( K i ) values of <2 nM, 250 nM, and 350 nM for FABP4, FABP5, and FABP3, respectively ( 10 ) (12)(13)(14), with one compound displaying an IC 50 value of 600 nM in a fl uorescence polarization (FP) assay ( 15 ), and another compound in the same series an IC 50 value of 49 nM in a scintillation proximity assay ( 16 ). However, no biological characterization in cell-based or in vivo assays has been reported.…”