Further studies will be needed to define this point and to clarify the mechanisms whereby Notch signaling sustains eIF4E activity in CLL cells, given that Notch targeting does not have any effect on the phosphorylation levels of 4E-BP1 and MNK1, which in other cell types, are two key upstream regulators of eIF4E activity [41, 42]. This evidence concerns the gene EIF4E and B-cell chronic lymphocytic leukemia.