FLAP (Arachidonate 5-lipoxygenase-activating protein) is an integral membrane protein, which facilitates the transfer of the substrate arachidonic acid (AA) to 5-lipoxygenase (5-LO) to produce leukotrienes (LTs), and is shown to be indispensable for cellular LT biosynthesis. FLAP transfers arachidonic acid to 5-LOX protein, thereby enabling this enzyme to efficiently produce oxidized lipid products (mainly eicosanoids) that are important in cell growth, differentiation and death particularly apoptosis.