Effect of CK2 inhibitors on PTEN and Akt1 phosphorylation. PBMCs from 6 patients with CLL were treated with apigenin for 2 days in cocultures. Apigenin inhibited phosphorylation of PTEN at Ser-380 residue and its downstream target Akt1 pSer-473 as shown by Western blotting in a representative case (A), and this was associated with a significant decrease in cell viability as shown by annexin V/PI staining (B). The effect of CK2 inhibitor is more significant on CD19⁺ cells compared with T cells and monocytes. The effect of 3 CK2 inhibitors (apigenin, TBB, DRB) on PTEN and Akt1 dephosphorylation and on cell viability in coculture was confirmed in samples of 3 patients with CLL as shown (C and D, respectively). GAPDH indicates glyceraldehyde-3-phosphate dehydrogenase