Acne vulgaris(AV) is a chronic disease of the pilosebaceous unit which is most common during adolescence. Four factors are believed to play a key role in the development of acne lesions: excess sebum production, disturbed keratinization within the follicle, colonization of the pilosebaceous duct by Propionibacterium acnes,and the release of inflammatory mediators into the skin.             Evaluation of serum levels of lipocalin2(LCN2) in acne vulgaris patients.Serum LCN2 concentrations were measured in 30 patients with AV and 30 healthy controls using enzyme-linked immunosorbent assay (ELISA).Serum levels of LCN2 in patients with AV were found to be higher than in healthy controls (p < 0.001). Increased serum LCN2 probably reflect the role of LCN2 in the pathogenesis of AV.