ALOX5(ARACHIDONATE 5-LIPOXYGENASE),also known as LOG5 or 5-LO(5-LIPOXYGENASE), is an enzyme that in humans is encoded by the ALOX5 gene. ALOX5 is a member of the lipoxygenase family of enzymes which also transforms EFAs into leukotrienes and is a current target for pharmaceutical intervention in a number of diseases. The enzyme 5-lipoxygenase catalyzes 2 reactions in the formation of leukotrienes. The ALOX5 gene is mapped to chromosome 10q11.21 based on an alignment of the ALOX5 sequence with the genomic sequence. Human 5-LO contains 3 nuclear localization sequences (NLSs) and a phosphorylation site involved in nuclear localization. Compared with age-matched 5-LO competent mice, the 5-LO knockout mice developed less right heart hypertrophy. Pharmacologic inhibition or ALOX5 gene disruption resulted in a significant decrease of beta-amyloid production and gamma-secretase levels. ALOX5 activity is short-lived, apparently in part because of an intrinsic instability of the enzyme.