The group of SLE patients with serum uromodulin levels <83 ng/mL (n = 29) had higher rSLEDAI scores (6.0 vs. 4.0; p = 0.01), higher SLICC renal activity scores (3.0 vs. 0.0; p = 0.01), and higher proteinuria values (0.6 g/24 h vs. 0.3 g/24 h; p = 0.05) than the group of SLE patients with serum uromodulin levels ≥ 83 ng/mL (n = 85). This evidence concerns the gene UMOD and systemic lupus erythematosus.