Bax degradation activity in primary CLL cells. The postnuclear supernatants were extracted from peripheral blood lymphocytes (PBL) from a healthy donor and CLL cells and incubated with the ubiquitin and ATP regeneration system for up to 5 hours. Twenty micrograms of protein were loaded in each lane for sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE). The Bax (clone 2D2) antibody was used in 1:1000 dilution and the β-actin antibody was used at 1:10 000 dilution. Numbers under each pair of blots are ratios of Bax/β-actin. Top panel shows results for a normal donor; lower 4 panels are cases of CLL.