IL-38 mRNA levels were strongly elevated in the synovial tissue of patients with RA compared to patients with osteoarthritis (OA), and associated with the total leukocyte counts in the synovial fluid, especially the number of monocytes, and expression of IL-1β, IL-1Ra, CCL3, and CCL4 (10, 11) (Table 1). The gene discussed is IL1F10; the disease is rheumatoid arthritis.