We also found reduced serum levels of soluble CD40 (median levels RA = 482.3 pg/ml vs. controls = 608.3 pg/ml, p = 0.02) and CD40L (median levels RA = 4,446.3 pg/ml vs. controls = 12,450.5 pg/ml, p < 0.0001). The gene discussed is CD40; the disease is rheumatoid arthritis.