Such as promoter hypermethylation and BRCA1 inactivation in sporadic breast and ovarian tumors [3], hypermethylation of the APC (adenomatous polyposis coli) gene promoter region is involved in human colorectal carcinoma [4], incidence and functional consequences of hMLH1 promoter hypemethylation in colorectal carcinoma[5], hypermethylation around the promoter may be a mechanism of E-cadherin inactivation in human carcinomas [6]. The gene discussed is MLH1; the disease is colorectal carcinoma.