The concentration of Calgranulin B in serum (or other fluids such as synovial fluid) correlates with disease activity in a wide range of inflammatory conditions, including rheumatoid arthritis [27], pauciarticular onset juvenile rheumatoid arthritis [26]; inflammatory bowel disease [28]; chronic airway inflammation [29]; kidney allograft rejection [30] and acute appendicitis [31]. The gene discussed is S100A9; the disease is rheumatoid arthritis.