APOL1 and nonpapillary renal cell carcinoma: Among the top 20 upregulated genes that were highly expressed in ccRCC compared to normal tissues (Supplementary Figure S1B), TGFBI, PLOD2, TMEM45A, FCGR1C, HIST1H2BH, CCL5 and APOL1 were closely correlated to poor survival rate in ccRCC patients.