IL‐22 is up‐regulated in patients with rheumatoid arthritis,31, 32 Crohn's disease,33, 34 psoriasis35, 36 and atopic dermatitis,37, 38 whereas it is down‐regulated in the serum of patients with sarcoidosis and systemic lupus erythematosus. This evidence concerns the gene IL22 and systemic lupus erythematosus.