Recent findings suggested that expression of IL-38 was abnormal in chronic inflammatory diseases, especially rheumatic autoimmune diseases, such as systemic lupus erythematosus (SLE) (8, 9), rheumatoid arthritis (RA) (10, 11), psoriasis (10, 12), and inflammatory bowel diseases (IBD) (10). The gene discussed is IL1F10; the disease is rheumatoid arthritis.