Serum CD44 level was significantly increased in patients with active LN compared to quiescent LN patients, patients with active non-renal SLE, CKD patients or healthy subjects (13.58 ± 1.73, 1.57 ± 0.22, 0.57 ± 0.11, 0.67 ± 0.08 and 0.37 ± 0.05ng/ml respectively, P<0.001, active LN vs remission LN, non-renal active SLE, CKD and healthy subjects) (Figure 5A). Here, CD44 is linked to systemic lupus erythematosus.