Leukotriene B4 (LTB4) is a major product of arachidonic acid metabolism and is formed via the 5-lipoxygenase pathway. LTB4 stimulates leukocyte functions including lysosomal enzyme release, adhesion, and aggregation of polymorphonuclear leukocytes. LTB4 has been implicated as a potent mediator of inflammatory diseases and immunoregulation.