Gene expression signatures associated with clinical outcome of patients with HL. (A) The genes identified in a supervised analysis (t test) as differentially expressed (FDR below 0.15) between the 2 groups of patients (favorable versus unfavorable treatment response) were subjected to hierarchic clustering using the SOTA algorithm. Four main clusters or signatures were obtained (see “Gene expression analysis”). For the cell lines and the centroblasts, the average of 2 hybridizations is shown. (B) Histogram representing the average expression value of each signature in the different groups of samples (cell lines, centroblasts, normal lymph nodes, favorable outcome HL, and unfavorable outcome HL). Error bars represent standard deviations. C1 to C4 represents clusters 1 through 4.