Given that aberrant methylation of p16ink4 promoter is frequently observed in adenocarcinoma arising from the gastrointestinal tract,40,41 MSP experiments were performed and CDKN2A (p16ink4) promoter hypermethylation was detected in 4 out of 5 tumour samples (Supplementary Figure 5). Here, CDKN2A is linked to neoplasm.