We confirmed these results in CLL patient cells cultured with CD154 and IL‐4, a combination of factors that mimics some of the main features of the proliferation centre microenvironment.38, 39 In these conditions, CUDC‐907 was shown to be one of the most efficient at reducing cell viability and induce cell death as well, which also happened at nanomolar concentrations and in a dose‐dependent manner (Figure 1C and D). Here, IL4 is linked to B-cell chronic lymphocytic leukemia.