UMOD and systemic lupus erythematosus: We observed lower serum uromodulin levels in SLE patients with renal activity, with respect to those without renal activity, using a cut-off renal SLICC score of ≥ 5.0 (p<0.001), in the same way that we observed a lower sUromod/eGFR index score in SLE patients with renal activity (p<0.001).