Fig. 1

SNV distribution and phylogeny of tumours. a Hypothetical phylogenies with the field effect and monoclonal origin hypotheses. b Number of SNVs with respect to occurrence among samples. Tumour 1 Apex, Tumour 1 Base, Tumour 2 Base/Apex, Normal private: SNVs only in that sample. As there are only 3 normal private mutations their bar is too small to be visually noticeable. All samples shared: SNVs in all 4 samples, representing the individual genotype. Other: SNVs in the normal mucosa sample and in one or in two tumour samples. All tumours shared: SNVs in all 3 tumour samples but not in normal mucosa. Other tumour-associated: SNVs in found in one or two but not all tumours and not in normal mucosa. c Neighbour-joining tree of the 4 samples and the human reference genome based on 1628–1733 high-confidence SNVs. Bootstrap support for each internal node is indicated. d Proportion of functional SNVs among all SNVs shared among all 4 samples (n = 143–182), and SNVs shared among all 3 tumours (n = 116–152). ***: Fisher’s exact test p < 0.001