UMOD and systemic lupus erythematosus: In a cross-sectional study of 114 SLE patients, low serum uromodulin levels and a low serum uromodulin/eGFR index were correlated with higher scores of renal systemic lupus erythematosus disease activity index (SLEDAI), systemic lupus collaborating clinics (SLICC), kidney function, and proteinuria.