CDH1 and gastric cancer: All the three GC cell lines SGC-7901, BGC-823 and MGC80-3, and the human gastric mucosal epithelial cell line GES-1 showed significant methylation pattern at the CpG sites of CDH1 exon 8 and the nearby exons (Fig. 3, Additional file 2: Figure S1 and Additional file 3: Figure S2).