CA9 is a known antigen currently being targeted for RCC immunotherapy (Divgi et al, 1998; Steffens et al, 1999; Uemura et al, 1999; Grabmaier et al, 2000; Li et al, 2001; Bui et al, 2003; Kennett, 2003). This evidence concerns the gene CA9 and renal cell carcinoma.