To confirm the robust nature of cancer-related signatures identified in this study, comparative changes in the methylation status of a selection of genes with potential clinical relevance (SMAD3, SPON2, FOXF1, and FENDRR) were validated in an independent set of gastric CAMs, patient-matched ATMs and unrelated NTMs by pyrosequencing and quantitative PCR. This evidence concerns the gene SMAD3 and cancer.