miRNA expression profiling of DLBCL cell lines. (A) Unsupervised hierarchical clustering of DLBCL cell line samples using all miRNAs with no more than 50% missing values. (B) Hierarchical clustering of the same samples using only the 9 miRNAs with differential expression between the ABC and GCB DLBCL subtypes based on SAM analysis. (C) The 39 miRNA cell-of-origin classifiers shown in Figure 1B are used for hierarchical clustering of cell lines and normal tonsillar lymphocyte subpopulations. Mean centered log ratios for each miRNA are represented. Missing values are in gray. CB indicates centroblast; MC, memory B cell; N, naive B cell; T, T cells; GCB, germinal center–like DLBCL; and ABC, activated B cell–like DLBCL.