MKI67 and B-cell chronic lymphocytic leukemia: TAK-659 treatment inhibited co-culture-induced proliferation in a dose-dependent manner, being 10 μM the TAK-659 dose at which the percentage of Ki-67 positive CLL cells did not significantly differ from that in unstimulated CLL cells (Figure 4A) (mean % of Ki-67-positive cells: 7.00 ± 1.49 in untreated controls vs. 3.39 ± 0.76 in TAK-659 0.1 μM-treated CLL cells, P < 0.01 vs. 1.72 ± 0.20 in TAK-659 1 μM-treated CLL cells, P < 0.01 vs. 1.27 ± 0.18 in TAK-659 10 μM-treated CLL cells, P < 0.001).