The PI-3 kinase inhibitor wortmannin and the DNA-PKcs inhibitor NU7026 sensitize resistant B-CLL cells to γ-irradiation-induced apoptosis. R indicates resistant B-CLL (n = 5 samples); and S, sensitive B-CLL (n = 7 samples). (A) B-CLL cells were either left untreated (NT) or treated with 1 μM wortmannin alone (WM), with 10 Gy irradiation alone (IR) or with 1 μM wortmannin and 10 Gy irradiation (IR+WM). (B) B-CLL cells were either left untreated (NT) or treated with 10 μM NU7026 alone (NU7026), with 10 Gy irradiation alone (IR), or with 10 μM NU7026 and 10 Gy irradiation (IR+NU7026). Percentages of apoptotic cells are means (± SEM) of duplicate experiments on n B-CLL samples.