With the exception of CXCL5 that was largely not detectable in the plasma of primary RCC patients, our findings confirm previous reports describing the presence of CXCL1, CXCL3, CXCL5 and CXCL8 in the plasma and tumors of patients with metastatic RCC [21]. Here, CXCL3 is linked to renal cell carcinoma.