Quiflapon (MK-591) is a selective and specific 5-lipoxygenase-activating protein ( FLAP ) inhibitor with an IC 50 of 1.6 nM in a FLAP binding assay. Quiflapon is also a potent and orally active Leukotriene biosynthesis (LT) inhibitor, shows IC 50 values of 3.1 and 6.1 nM in intact human and elicited rat PMNLs, respectively. Quiflapon induces cell apoptosis .