DNA methylation patterns of the CDH1 promoter in non-cancerous gastric tissue from patients with sporadic gastric cancer determined by bisulfite sequencing analysis. At least 8 subcloned promoter fragments were sequenced in each sample, and the results for 15 representative samples are shown. Each horizontal row represents a single allele. The positions of the CpG sites are numbered at the top of the column. Methylated CpG sites are shown as black boxes, and unmethylated CpG sites as white boxes. The far right column indicates the allele of the -348_-347insA, -161C>A, or -73A>C polymorphism: wild-type allele, red; variant-type allele, sky blue.