Fig. 1

Methylation status of gene promoters involved in the early stages of colon carcinogenesis. a The methylation status of APC, CDH13, MGMT, MLH1 and RUNX3 gene promoters was assessed by methylation specific-PCR of colonic mucosa specimens derived from patients with colon carcinogenesis. The frequency of methylation of each gene among the different patients groups is shown. b The frequency of total methylation, defined as the sum of the methylated genes detected (range 0–4), among the different patients groups is shown. CTRL, healthy control; DYS, dysplasia and adenoma