As 20 ccRCCs showed undetectable VHL (Fig. 2B, see the dots on the X-axis) versus 5 ccRCC with undetectable RKIP (Fig. 2A), the tumorigenesis of ccRCC most likely relies heavily on the loss of VHL function and on the partial reduction of RKIP action. This evidence concerns the gene PEBP1 and nonpapillary renal cell carcinoma.