The commonly used kidney function indicators in clinic, such as urea, creatinine (Cr), uric acid (UA), cystatin C (CysC), complement C1q (C1q), neutrophil gelatinase-associated lipocalin (NGAL), and estimated glomerular filtration rate (eGFR), can evaluate the kidney function of patients with RCC, but cannot indicate kidney tumors. This evidence concerns the gene LCN2 and renal cell carcinoma.