In citrate plasma, VEGF levels were elevated in non-RCC patients, but this could be explained by a combination of increased platelet activation during blood harvesting, and by a two-fold increase in VEGF content of individual platelets (controls: 3.4 IU/106, non-RCC: 6.2 IU/106 platelets, p = 0.001). This evidence concerns the gene VEGFA and renal cell carcinoma.