POLE and nonpapillary renal cell carcinoma: Univariate and multivariate Cox regression analyses revealed that POLE was the most clinically significant marker for predicting the outcomes of patients with ccRCC (p < 0.01) (Figures 6A,B) To verify whether the expression of POLE was higher in ccRCC samples compared with normal kidney tissue, we performed IHC analysis and found that expression of POLE was higher in ccRCC than in normal kidney tissues (Figure 6C).