It therefore appears that the best strategy for isolating TICs of ccRCC is to include known VHL-HIF targets in addition to stem cell markers from clinical samples, such as the studies of Addla et al. and Fendler et al. [71, 81], which both identified CXCR4, signaling pathways WNT (β-catenin) and NOTCH1, and stem cell marker CD133 and PAX2, as signature markers (Studies 3 and 8, Table 1). This evidence concerns the gene CXCR4 and nonpapillary renal cell carcinoma.