The serum levels of S100A8 (calgranulin A or myeloid-related protein 8, MRP8) and S100A9 (calgranulin B or MRP14) were increased in patients with systemic JIA and AOSD, and these factors were deposited in the skin or lymph nodes of the latter patients (21, 26, 27). The gene discussed is S100A9; the disease is adult-onset Still disease.