The present study has partially elucidated the biological function of circFOXO3 in ccRCC progression, but a more in-depth investigation using clinical samples is required to confirm the results, as well as to further investigate the KLF16/circFOXO3/miR-29a-3p/miR-122-5p axis. This evidence concerns the gene KLF16 and nonpapillary renal cell carcinoma.