We found that in 15 of the 18 samples where Notch1 and Notch2 downregulation reduced CLL cell viability, there was a decrease in Mcl-1 levels compared with siCtrl cells, whereas in the four samples with Notch-independent viability, Mcl-1 levels remained unchanged (Table 2, Figures 1C and 1D). Here, MCL1 is linked to B-cell chronic lymphocytic leukemia.