Figure 2

Global miRNA expression analysis of 51 human breast cancer cell lines. Unsupervised clustering across the breast cancer cell lines using the 87 most variably expressed miRNAs. Yellow and blue, high expression and low expression of the particular miRNA in the particular sample, respectively. Cell lines in the dendrogram of the hierarchical clustering based on miRNA expression are coded according to their intrinsic subtypes and depicted at the bottom of the figure (for color codes see Figure 1 caption). Red boxes enlist the groups of miRNAs that show the most robust cluster-specific differential expression in the cell lines. miRNA hsa-miR-21 in the red box of minor cluster failed to reach our criteria of fold change ≥ 1.5.