LTA4H is a bifunctional zinc metalloenzyme with dual pro- and anti-inflammatory roles in immune regulation. As an epoxide hydrolase, it catalyzes conversion of leukotriene A4 (LTA4) to leukotriene B4 (LTB4), a potent pro-inflammatory mediator that recruits neutrophils. Concurrently, its aminopeptidase activity counteracts inflammation by cleaving Pro-Gly-Pro, a neutrophil attractant derived from collagen degradation, and participates in biosynthesis of anti-inflammatory resolvins from eicosapentaenoic acid. Genetic variation in LTA4H influences responsiveness to leukotriene-modifying asthma medications 1. In colorectal cancer, elevated LTA4H and LTB4 signaling correlate with worse survival; bestatin-mediated LTA4H inhibition reduced LTB4 production and tumorigenesis in preclinical models and patient-derived xenografts 2. Conversely, recent evidence suggests LTA4H may play a protective role in hepatocellular carcinoma through regulation of the tumor microenvironment 3. LTA4H polymorphisms also modulate susceptibility to extra-pulmonary tuberculosis, particularly tuberculous meningitis, in East Asian populations 4, though specific polymorphisms were not predictive of paradoxical inflammatory reactions in extrapulmonary disease 5. Acebilustat, a selective LTA4H inhibitor, represents a therapeutic approach for modulating leukotriene-dependent inflammatory diseases.