A selective, cell-permeable inhibitor of CK2 (IC50 = 0.11 µM, Ki = 77 nM) that has minimal effect on a panel of 28 other kinases; induces cell death in Jurkat adult T cell leukemia cells (DC50 = 7.7 µM), driving caspase-dependent degradation of poly-ADP ribose polymerase while inhibiting CK2 activity.