S100A8 and adult-onset Still disease: 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).