Since the original mRNA levels of CCND1 in these RCC cell lines (mean Ct values of RT-qPCR range from 19.7 to 21.5) were much higher than the levels of miR-224-5p (RT-qPCR Ct values > 30), it can be inferred that the effects of miR-224-5p inhibitors on cyclin D1 protein expression were relatively weak. This evidence concerns the gene CCND1 and renal cell carcinoma.