A 2-dimensional hierarchical cluster analysis of 7 tonsil BC (TBC), 7 tonsil PC (TPC), 7 bone marrow PC (BPC), and 7 MM PC samples clustered based on the correlation of experimental expression profiles of 3288 probe sets.

The clustering is presented graphically as a colored image. Along the vertical axis, the analyzed genes are arranged as ordered by the clustering algorithm. The genes with the most similar patterns of expression are adjacent to each other. Experimental samples are arranged the same way along the horizontal axis; those with the most similar patterns of expression across all genes are adjacent to each other. Sample groupings can be further described by following the solid lines (branches) that connect the individual components with the larger groups. The color of each cell in the tabular image represents the expression level of each gene, with red representing an expression greater than the mean, green representing an expression less than the mean, and the deeper color intensity representing a greater magnitude of deviation from the mean.