CYP4F3 is a cytochrome P450 enzyme located on chromosome 19.2 that primarily catalyzes omega-oxidation of polyunsaturated fatty acids (PUFAs) 1. Its major function is converting leukotriene B4 (LTB4), a pro-inflammatory mediator, into the less active 20-hydroxy-LTB4, thereby regulating innate immune responses 1. CYP4F3 also metabolizes arachidonic acid to 20-hydroxyeicosatetraenoic acid (20-HETE), which modulates vascular tone and sodium handling 1. The enzyme exhibits tissue-specific expression through alternative promoters and exon splicing, generating neutrophil (CYP4F3A) and liver (CYP4F3B) isoforms with different substrate affinities 2. Clinically, CYP4F3 dysfunction has multiple disease implications. A missense mutation (p.L375V) impairing enzyme activity by 50% causes elevated systemic LTB4 levels associated with immune exhaustion and inflammation-related pathology 3. Genetic polymorphisms in CYP4F3 are associated with gestational hypertension and preeclampsia, conditions characterized by altered eicosanoid metabolism 4. CYP4F3 variants show gene-environment interactions with dietary fatty acid intake in inflammatory bowel disease pathogenesis 5, and pathway analysis identifies CYP4F3 variants as potential contributors to lung cancer susceptibility, particularly in smokers 6. Additionally, CYP4F3 expression is induced by benzene metabolites, potentially contributing to benzene-induced hematotoxicity 7.