Fig. 4

Overview of cluster 3 samples, showing a shift toward increased MAPK pathway expression. a ESR1 expression in the 4 clusters, red indicates samples labeled as ER+ in their primary disease, blue ER negative in primary disease. b The ESR1 module score over samples, grouped by the meta ER status: a combination of MBC ESR1 expression and reported ER status in primary (i.e. ‘pos.to.low’ indicate samples with a reported ER+ status in primary but with low ESR1 expression in the metastatic lesion and vice versa for ‘neg.to.pos’). c, d MAPK signature expression over cluster groups (c) and meta ER status (d). e Summary of characteristics of cluster 3 samples. Top 2 tracks show log2 CopyNumber (dotted line indicates CN of 2) and mutation of ERBB2. The third track indicates patients who received anti-HER2 therapy prior to biopsy. Track 4 shows ER status: brown indicate cases of which the primary tumor was ER positive but the metastatic biopsy has low ESR1 expression, i.e. ER pos-to-low. Green: ER neg-to-high, orange: concurrent ER pos, gray: concurrent ER neg. Bottom track shows expression levels of the MAPK signature, and dotted line indicates median