DPEP2 (MBD-2) belongs to the membrane-bound dipeptidase family. There are three members of this family as membrane-bound dipeptidase-1 (MBD-1),membrane-bound dipeptidase-2 (MBD-2) and membrane-bound dipeptidase-3 (MBD-3).MBD-2 is expressed at highest levels in lung, heart, and testis and at some what lower levels in spleen.MBD-2 is membrane-bound through a glycosylphosphatidyl-inositol linkage and probably is a metalloprotease which hydrolyzes leukotriene D4 (LTD4) into leukotriene E4 (LTE4).It is generally recognized that rapid cleavage of LTD4 is important in inactivating the broncho-and vaso-constrictive effects of cysteinyl LTs in asthmatic and inflammatory processes.