In an earlier study, we found elevated levels of cytoplasmic p21 expression at time of surgery were associated with a worse prognosis in patients with metastatic ccRCC[26] consistent with the data in the present study; assessment of PTEN and p21 status in a small set of ccRCC (N = 9) from the University of Colorado Hospital archives showed loss of PTEN and elevated levels of p21 staining in every tumor, as compared to unaffected kidney samples from age and sex matched controls (R. Weiss, J. Modiano, and K. Shroyer, unpublished observations). This evidence concerns the gene PTEN and neoplasm.