ALOX5(arachidonate 5-lipoxygenase) is also named as LOG5,5-LO and belongs to the lipoxygenase family. It catalyzes the first step in leukotriene biosynthesis,and plays a role in inflammatory processes. It is a 78 kDa iron-containing enzyme that translocates from the cytosol to associate with FLAP,and converts arachidonate in two steps into the unstable intermediate LTA4. It is essential for cysteinyl-leukotriene (cys-LT) production,critical mediators in asthma.