ALOX5AP (arachidonate 5-lipoxygenase-activating protein) is a membrane-anchoring cofactor essential for leukotriene biosynthesis. It functions by binding arachidonic acid and facilitating its transfer to ALOX5 (5-lipoxygenase), the rate-limiting enzyme in leukotriene production. ALOX5AP serves as a critical platform for this interaction at the endoplasmic reticulum and nuclear membrane, and also binds MK-886, a leukotriene biosynthesis inhibitor. Beyond its canonical role in immune cell signaling, ALOX5AP is implicated in pathological processes including fibroblast-mediated lymphocyte recruitment via CXCL8 and CXCL10 in chr13 inflammation 1, and angiogenesis. Clinically, ALOX5AP polymorphisms are associated with cardiovascular and cerebrovascular disease. Specific variants show associations with myocardial infarction (HapA haplotype) and coronary heart disease (HapB haplotype, rs17222842) 2. Multiple ALOX5AP polymorphisms (rs10507391, SG13S114, rs17222919) are associated with ischemic stroke risk, though associations vary by ancestry and stroke subtype 3, 4, 5, 6. These genetic associations suggest ALOX5AP's role in thromboinflammatory pathways underlying vascular disease.