E2A-HLF suppresses p53-induced apoptosis in M1p53ts_val cells. (A) Viable cell counts (means of triplicate determinations) performed at serial times after a shift in temperature to 32°C for 3 clones (7, 24, and 25) expressing E2A-HLF or for control cells, with or without the addition of IL-6. Comparisons of cell survival at 24 hours between controls and clones 7, 24, and 25 yielded P values of .004, .036, and .004, respectively. (B) Flow cytometric TUNEL assay of TdT-labeled DNA performed in cells grown at 37°C or 24 hours after a shift to 32°C. Respective differences in the percentages of cells undergoing apoptosis between the control and clones 7, 24, and 25 were statistically significant at the P < .0001 level.