Zhao et al. found that the plasma levels of IL-17A and IL-22 in patients with SLE were higher than those in healthy controls, and they showed that Th17 and IL-22 levels were positively correlated with the SLE disease activity index (SLEDAI), indicating that IL-22 and IL-22+CD4+ T cells play an important role in the pathogenesis of SLE (66). Here, IL17A is linked to systemic lupus erythematosus.