However, it has been reported that both serum leptin levels and the leptin receptor expression in tissue are higher in patients with renal cancer with venous invasion compared to patients without venous invasion, indicating a significant association with the histological type and metastasis to lymph nodes, as well as shorter disease-free survival in patients with serum leptin of ≥5.0 ng/mL [203]. This evidence concerns the gene LEP and renal carcinoma.