Attributes of the enrichment score. (A) A heatmap representation of LIMMA linear coefficients for ES cells. The heatmap depicts linear coefficients derived from a pairwise comparison of expression values in ES cells and every other cell type/tissue in the panel. For illustration purposes only transcription factors are shown, are sorted vertically by the enrichment score (sum of coefficients in each row). (B) Expression values (black) and their standard deviation (black vertical lines), z-scores (red) and enrichment scores (yellow) for TBX21 and GAPDH. For illustration purposes only the top 10 and bottom 10 expressing tissues are shown. The left y-axis indicates expression values on log2 scale and z-score values. The right blue y-axis indicates enrichment scores. A distribution of enrichment scores was obtained from the highest score for each probe on the array and the percentiles of that distribution are shown in blue dotted lines.