Four of these genes (APC, EYA4, RBP1 and SFRP4) have previously been reported to be hypermethylated in Barrett’s oesophagus lending support to our candidate gene list.23 30–33 It is also interesting that some other genes that had been reported to be differentially methylated previously (CDX2, B3GAT2 and vimentin) were found to be more highly methylated in Barrett’s oesophagus compared with normal squamous biopsies that did not reach statistical significance (<0.05) and so were not taken forward (online supplementary figure 2). This evidence concerns the gene CDX2 and Barrett esophagus.