To investigate whether CTHRC1 gene expression is regulated by an epigenetic mechanism, specifically promoter CpG methylation, we treated colon cancer cell lines that showed low CTHRC1 expression (LS174T, SNUC1, SW480, and HT-29) with the demethylating agent, 5-Aza-dC, and then examined CTHRC1 mRNA expression by RT-PCR. This evidence concerns the gene CTHRC1 and malignant colon neoplasm.