a, Top, unsupervised hierarchical clustering of 27 MCF7 strains based on the allelic fractions of their non-silent SNVs. Colours as in Fig. 1. Bottom, corresponding heat map of the allelic fractions of non-silent mutations present in a subset of the strains. b, The distribution of allelic fractions of non-silent mutations across strains. c, The cellular prevalence of mutation clusters across MCF7 strains identified by a PyClone analysis. Mutation clusters with differential abundance (a difference in cellular prevalence (ΔCP) > 0.15), the clonal cluster (cluster 6; CP ≈ 1 in all clones) and a cluster unique to MCF7-M (cluster 12) are shown. n = mutations per cluster, data are mean ± s.e.m. d, Top, unsupervised hierarchical clustering of 27 samples of DNA-barcoded MCF7-D based on barcode representation. Dendrogram branches are coloured by culture condition. Bottom, corresponding heat map of barcode representation. ETP, early time point; RPMI, RPMI 1640 medium; DMEM, DMEM medium; DMSO, RPMI 1640 with 0.05% DMSO; ESTDEP, oestrogen-depleted RPMI 1640 medium; BORT, bortezomib (500 nM; 48 h exposure) followed by RPMI 1640.