Table 2

Non-synonymous variants in COSMIC genes shared between the metaplastic columnar epithelium without goblet cells and the OAC

Gene	Chromosome	Position	Reference	Lineage
ERCC3	2	128030539	T	C
ECT2L	6	139186237	G	A
AKAP9	7	91691758	C	A
MAML2	11	95712231	T	C
GOLGA5	14	93301904	G	A
TP53	17	7577121	G	A
NCOR1	17	16049843	C	T

The TP53 somatic variant is the only previously reported recurrent variant and was selected for resequencing. The majority of the variants used to derive the phylogeny of this patient's Barrett's segment are synonymous (see online supplementary figure S4).
OAC, oesophageal adenocarcinoma.