ARID1A and cancer: The whole‐genome and whole‐exome sequencing of Barrett's and cancer pairs have shown the mutational density of SNVs in Barrett's to be 2.8–6.76 SNVs/Mb with mutations occurring in a number of genes which are not in this hot‐spot panel including EYS, SYNE1, ARID1A, SMARCA4, TRIM582, 32.