CDK6 and nonpapillary renal cell carcinoma: Restoration of CDK4, CDK6 and Caprin1 partially, but significantly, rescued the G1/S transition impaired by miR-1(Figure 5A), suggesting that downregulation of CDK4, CDK6, Caprin1 were functionally important for the inhibitory effect of miR-1 on ccRCC cell proliferation.