IL9 and systemic lupus erythematosus: IL-9 cytokine makes an important contribution to allergic reactions; it stimulates eosinophil and mast cell proliferation and recruitment and is implicated in the pathogenesis of allergic diseases, such as rhinitis, asthma, and atopic and contact dermatitis, but also to autoimmune diseases, including SLE, RA, psoriasis, and inflammatory bowel disease.