TCF7 and breast cancer: To assess the significance of elevated expression of canonical WNT target genes in human HER2 breast cancer, the KM plotter resource (Nagy et al., 2018) was used to mine relapse-free survival data for unselected human breast cancers, for HER2-amplified breast cancers and for HER2-non-amplified breast cancers stratified according to MYC, TCF7, AXIN2 and WIF1 expression (Fig. S7).