IL4 and B-cell chronic lymphocytic leukemia: Analysis of newly generated RNA demonstrates that transcription is increased in CLL cells with the addition of CD40L/IL4 while treatment with 5,6-Dichlorobenzimidazole 1-b-D-ribofuranoside (DRB), a potent RNA Pol II inhibitor (negative control), significantly reduced RNA synthesis (Figure 6A,B; >50% repression after 18 h DRB treatment).