Although KLF6 was shown to be a putative direct PDGFB transcriptional activator in ccRCC, it remains to be elucidated whether ccRCC cells secrete PDGF-BB (hereinafter referred to as PDGFB) and whether KLF6 is involved in modulating this process. This evidence concerns the gene KLF6 and nonpapillary renal cell carcinoma.