Next, we verified that CD44 was downregulated when transfected with siRNAs for circPPP6R3 or miR-1238-3p mimics both in RNA and protein levels in ccRCC cells, while an upregulation effect was observed when transfected with circPPP6R3-overexpressing plasmids or miR-1238-3p inhibitors (Fig. 7A, B). This evidence concerns the gene CD44 and nonpapillary renal cell carcinoma.