APP and Alzheimer disease: Interestingly, recent studies showed that hippocampi from patients with Alzheimer’s disease (AD) have higher 5LO immunoreactivity when compared with healthy controls, and that the genetic absence of 5LO results in a significant reduction of the brain amyloidotic phenotype of amyloid-β precursor protein (APP) transgenic mice (that is, Tg2576) [4,5].