NOTCH1 and B-cell chronic lymphocytic leukemia: As shown in Fig. 5, the ratios of apoptotic cells in NOTCH1-mutated CLL cells were significantly increased following treatment with GSI (ICN-specific inhibitor) and PDTC (NF-κB-specific inhibitor) compared with those obtained in unmutated- and normal B cells, and this effect was even greater when the two drugs were used (P=0.03).