This gene encodes an enzyme that is involved in the inactivation of the chemotactic factor, leukotriene B4. The encoded protein specifically catalyzes the NADP+ dependent conversion of leukotriene B4 to 12-oxo-leukotriene B4. A pseudogene of this gene is found on chromosome 1. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Mar 2009].