To gain a mechanistic insight into the synergistic cytotoxicity of of BIRB796 and venetoclax in CLL, we treated cells derived from three patients with CLL with 0.1% DMSO, 10 μM BIRB796, 1 nM venetoclax, and their combination for 24 h (Fig. 7e) and then used the SYTOX Blue/annexin V assay to assess the level of apoptosis. Here, ANXA5 is linked to B-cell chronic lymphocytic leukemia.