A recent study reported significantly higher plasma concentrations of IL-17 in 28 male subjects with high-functioning autism spectrum disorder (ASD) compared with 28 matched controls, and the patients with ASD also had higher plasma concentrations of other cytokines such as IL-1 receptor antagonist, IL-1β, IL-5, IL-8, IL-12 and IL-13 compared with controls. Here, IL5 is linked to autism spectrum disorder.