Gan H, et al. - Researchers examined the role of interleukin-27 (IL-27) in the pathogenesis of allergic rhinitis (AR). They determined the expression of interleukin 27 (IL-27) and Th2 cytokines (IL-4, IL-5, IL-13) using quantitative PCR and enzyme-linked immunosorbent assay in 22 patients diagnosed with AR and 20 normal controls. AR patients showed down-regulation of serum mRNA and protein levels of IL-27 compared with normal controls. Outcomes support the correlation of decreased IL-27 expression in AR with Th2 response and the utility of IL-27 as a potential target in the future treatment of AR.