While the upregulation of 5-LOX expression, leading to production of Cys-LTs and LTB4, has been reported at the site of atherosclerotic plaques (Whatling et al., 2007; Riccioni et al., 2010), increased 12-LOX activity or expression has been implicated in the functional loss of insulin secretion or production in beta-cells of the pancreatic islets, which may impair blood glucose regulation leading to the development of diabetes (Ma et al., 2010). This evidence concerns the gene ALOX15 and diabetes mellitus.