Fig. 4

Similarities of gene expression alterations of metastasis pairs from the same and different patients. A, Hierarchical cluster dendrogram representing the similarities of genome-wide log\(_2\)-ratio gene expression profiles comparing the intra- to the corresponding patient-matched extracranial metastasis sample. The color bars represent the tissue type in which the extracranial metastases occurred (upper bar, blue: lung; green: lymph node, yellow: skin, purple: soft tissue, pink: liver, light green: small intestine) and highlight the patient number by a color code (lower bar). Multiple metastasis pairs from the same patient are labeled with a number at the end of the corresponding identifier of the metastasis pair (see Table 1). Multiple metastasis pairs of each patient formed distinct clusters. Stability of individual clusters is quantified by the red AU value, where 100 means that a cluster was perfectly stable. B, Overlaps of the HMM-based predictions of differentially expressed genes for all pairwise comparisons of either two metastasis pairs from different patients (left boxplot) or for two metastasis pairs from the same patient (right boxplot). Overlap of HMM predictions are significantly different between pairs from different and same patients (Mann–Whitney-U-test: p < 0.003)