Western blotting of frozen tissue lysates from ten ccRCC/normal kidney matched pairs with tumour VHL mutation status defined in all but one pair (Fig. 1e) showed significant loss or downregulation of QPRT expression in ccRCC tissues compared to their normal counterparts in nine cases, although no relationship with VHL mutation status or mutation type was apparent. This evidence concerns the gene VHL and nonpapillary renal cell carcinoma.