The tissue type of a cancer has a strong influence on its CNA likelihood pattern.

<p>a) examples of individual chromosome segments, showing their observed CNA frequencies stratified by cell type. Each dot summarizes all samples classified under one particular ICD type, color-coded by root cell type. In the left panel, three chromosome segments are shown that exhibit strong differences between cell types; on the right, three negative examples without such a signal. All p-values were corrected for multiple testing according to Benjamini-Hochberg. b) the dendrogram (tree) has been obtained using hierarchical Ward clustering on the global frequency-normalized CNA profiles across all 160 genomic regions. Cancer types are again color-coded according to the cell type of origin, with the same legend as in a). Partitioning the tree by cutting at different heights produces multiple clusters; validation of those clusters based on the cancer origin (metric: Random Index) shows that the clustering works significantly better than expected at random.