The receptor for leukotriene B4 (LTB4). BLTR. is a member of the G prolein-coupled seven transmembrane domain receptor (GPCR) superfamily. This receptor is highly expressed on leukocytes, and mediates LTB4-induced leukocyte chemotaxis and activation. BLTR therefore participates in the recruitment of leukocytes to sites of pathogen invasion as part of the innate immune response, and also in the pathogenesis of inflammatory reactions in which LTB4 has been implicated. BLTR antagonists have successfully reduced leukocyte recruitment and tissue damage in animal models of inflammatory diseases, demonstrating the therapeutic potential of inhibiting BLTR in the treatment of pathologic inflammation.