ALCAM and systemic lupus erythematosus: In this cross-sectional study, urinary ALCAM levels were significantly increased in active LN patients (11.50 IQR (16.79) ng/mg) when compared to active SLE patients without renal involvement (3.51 IQR (6.20) ng/mg, p < 0.001), inactive LN patients (3.46 IQR (5.14) ng/mg, p = 0.023), inactive SLE patients without renal involvement (2.45 IQR (4.04) ng/mg, p < 0.001), and healthy controls (1.79 IQR (1.23) ng/mg, p < 0.001) (Fig. 1a).