CD44 level showed higher sensitivity and specificity than anti-dsDNA titre and C3 level in distinguishing between active LN and active non-renal SLE (sensitivity and specificity rates of 71.43% and 70.37% respectively for anti-dsDNA antibodies, and 85.71% and 86.84% respectively for C3) (Table 3). This evidence concerns the gene C3 and systemic lupus erythematosus.