BCR and B-cell chronic lymphocytic leukemia: Nonetheless, the concentration of ibrutinib used in these studies was sufficient to block BCR-signaling, as this same concentration (0.5 μM) was sufficient to inhibit the capacity of anti-μ to induce phosphorylation of ERK1/2 or DOCK2 in CLL cells of the same patient sample (Fig. 6e, f).