CYP24A1 and malignant colon neoplasm: A possible epigenetic control of CYP24A1 has been discussed in various recent reviews but has not been tested in the colon so far.14,27 Our study is the first to assess the methylation status of the CYP24A1 promoter in normal colon and colon cancer tissue, testing the hypothesis that the low expression of CYP24A1 in the normal colon mucosa could be due to promoter hypermethylation and that hypomethylation results in CYP24A1 overexpression in tumor tissue.