Performing binding experiments in the CAIX negative human renal cell carcinoma cell line CaKi 2 and in human umbilical vein endothelial cells (HUVEC), the binding capacity was found to be reduced to the background level with 0.4% of the applied dose per 106 cells on CaKi 2 and HUVEC cells (Figure 2A). This evidence concerns the gene CA9 and renal cell carcinoma.