PIK3R1 and nonpapillary renal cell carcinoma: The well-known clear cell renal cell carcinoma (CCRCC) CSC markers (ALDH1A1, CD44, CXCR4, DCLK1, CD105, ITGB1, NT5E, PIK3R1, PROM1 and THY1)20-27 were displayed in the featurePlot to verify the expression in the identified CDRCCCSC cluster (Supplementary Fig S5A, B).