Sensitivity of primary CLL cells to CK2 inhibition correlates with percentage of leukemia cells in the peripheral blood, clinical stage and β2 microglobulin levels. Correlation between percentage of CLL cells in the peripheral blood and viability index of purified CLL cells cultured with (A) 25μM TBB (n = 19) or (B) 25μM DRB (n = 14) for 48 hours. (C) Clinical stage A (n = 12) or stage B and C (n = 6) CLL patients. CLL viability after culture with 25μM TBB for 48 hours. Results are shown as mean ± SEM. (D) CLL patients with < 3 mg/L (n = 7) or > 3 mg/L (n = 9) β2 microglobulin. CLL viability after culture with 25μM TBB for 48 hours. Results are shown as mean ± SEM.