Induction of CD95-mediated apoptosis depends on LMP1 in LCL cells. pRT-1-LMP1CT (light gray bars) and pRT-1-LMP1wt (dark gray bars) transfected cells were pretreated with (+) or without (-) doxycycline for 36 hours. Cells were maintained ± doxycycline and additionally treated with the anti-CD95 agonistic mAb BG27 or with the CD95-neutralizing mAb BD29 for 24 hours, 48 hours, or left untreated. Apoptosis was quantified by flow cytometry, measuring the percentage of sub-G1 cells after cell staining with the propidium iodide dye of DNA.