ABCB1 and nonpapillary renal cell carcinoma: Univariate COX regression analysis for the survival of ccRCC patients was performed among the markers, determining that seven of them (ABCG2, ALDH1A3, ABCB1, CD105, DAB2IP, EZH2, SALL4) had the potential to be a prognosis factor for ccRCC patients (Figure 2F).