Thompson et al (2008) studied preoperative serum levels of B7x in 101 patients with CCRCC. Serum levels were higher in patients with a tumour thrombus, positive lymph nodes, and distant metastases. In a study on 74 patients, preoperative VEGF-A levels were independently associated with poor DSS (Klatte et al, 2007a). Li et al (2008) showed that higher preoperative carbonic anhydrase-9 levels correlate with diminished recurrence-free survival. This evidence concerns the gene VTCN1 and nonpapillary renal cell carcinoma.