Western blot analysis of Bcl-2 family in Hu-ECFCs. Hu-ECFCs were purified and recultured on day 8 (see Materials and Methods) with or without EP. The lettering above the panels indicates the day at which cells were subsequently removed from culture for analysis and whether they were cultured with (+) or without (−) EP. In the top panel, both lanes marked by asterisks contained proteins from HL60 cells as positive controls. In the bottom three panels, only the lane on the far right (*) contained proteins from HL60 cells as positive controls. The top panel shows Bcl-x (29.2 kD) probed using 5 μg rabbit polyclonal anti–Bcl-x antibody. The second panel shows Bax (21 kD) probed using 5 μg rabbit polyclonal anti-Bax antibody. The third panel shows Bak (23 kD, runs at 29 kD) probed using 5 μg mouse monoclonal anti-Bak antibody. The bottom panel shows Bcl-2 (26 kD) probed using 5 μg mouse monoclonal anti–Bcl-2 antibody.