Correlations between CHOP and XBP1 RNA expression and clinical behavior. Correlations between basal CHOP and XBP1 RNA expression and indolent/aggressive disease for (A-B) all CLL/all stages (n = 31), (C-D) stage A (M-CLL and U-CLL combined; n = 23), and (E-F) M-CLL (all stages; (n = 19). The statistical significance of differences was analyzed using Mann-Whitney test.