Thus, to check whether bortezomib affects CK2 activity, we treated MM and MCL cells with increasing concentrations of the proteasome inhibitor and assessed by western blot analysis the CK2-dependent phosphorylation of two known CK2 targets, i.e. the Hsp90 co-chaperone Cdc37 on Ser13 [20] and the NF-κB member p65 on Ser529 [42], [43]. Here, NFKB1 is linked to mantle cell lymphoma.