Currently, hypermethylation is thought to be one of the most common mechanisms by which tumor suppressor genes are downregulated in cancer cells.32,33 In different types of cancers (renal cell carcinoma, prostate cancer and malignant melanoma), HOXB13 is methylated at an upstream CpG island.34–36 DNMT3B, a DNA methyltransferase, is associated with the CIMP and may play a causal role in tumorigenesis.37 In the current study, DNMT3B was used as a biomarker to measure the methylation status of CRC tissue. The gene discussed is HOXB13; the disease is renal cell carcinoma.