To investigate the effects of the combination of TAK-659 with other BCR inhibitors we treated primary CLL cells with 0.1 μM TAK-659 combined with increasing doses of the Btk inhibitor, ibrutinib, and the PI3K delta-specific isoform inhibitor, idelalisib, and compared their viability rates. This evidence concerns the gene BTK and B-cell chronic lymphocytic leukemia.