(a) By unsupervised analyses, tumors separated into four sample groups (i.e. “clusters”), based on either differentially expressed mRNA patterns (left panel, showing 500 representative genes: m1–4) or differentially expressed miRNA patterns (right panel, showing 26 representative miRNAs: mi1–4). (b) Significant differences in patient survival were identified among either the mRNA-based clusters (left panel) or the miRNA-based clusters (right panel). (c) Numbers of samples overlapping between the two sets of clusters, with significant concordance observed between m1 and mi3 and between m3 and mi2; Red, significant overlap (P<1E-5, chi-squared test). (d) mRNA-miRNA correlations, for predicted targeting interactions. Rows indicate miRNAs from part a (indicated by cluster specific color bar); columns, mRNAs (5000 differentially regulated genes selected for average RPKM>10 and at least one predicted miRNA interaction); mRNA-miRNA entries with no predicted targeting show as white. To the right of the correlation matrix, t-statistics (Spearman’s rank) indicate group target enrichment.