It has been illustrated that 5-Aza-CdR is a DNA methylation inhibitor which leads to ubiquitin-dependent proteasome degradation of DNMT1.27, 28 To investigate whether 5-Aza-CdR-induced DNMT1 degradation contributed to KLF5 upregulation in ccRCC, DNMTs expression were detected in 786-O, RCC4 and A498 cells with or without 5-Aza-CdR treatment. The gene discussed is KLF5; the disease is nonpapillary renal cell carcinoma.