Sensitivity of casp8^−/− lymphomas to radiation and LPS-induced killing. (A) B-cell lymphomas from bcasp8^−/− mice (n = 12) and bcasp8^−/−p53^−/− mice (n = 4) and B cells from WT mice (n = 5) and p53^−/− mice (n = 4) were irradiated and their survival level examined 24 hours later using propidium iodide staining. (B) Expression of p53, p21, and Puma in bcasp8^−/− lymphomas and normal WT B cells was examined using Western blotting. Cells were either untreated or irradiated (6 Gy) and examined 4 hours after IR. (C) B-cell lymphomas from bcasp8^−/− mice (n = 8) and bcasp8^−/−p53^−/− mice (n = 4) and B cells from WT mice (n = 9) and CD19Cre;p53^fl/fl mice (n = 4) were treated with LPS and their survival level examined 24 hours later. *P < .05 for bcasp8^−/− and bcasp8^−/−p53^−/− samples versus WT and CD19Cre;p53^fl/fl samples by Student t test.