Relative changes of expression (RCE^spont) of Bcl-2 (A) and Bax (B) in T-ALL cells after culturing in standard medium for 24 hours.

RCE^spont values for Bax, but not Bcl-2, positively correlated with the extent of spontaneous apoptosis (ΔN^spont). RCE values were calculated as the ratio RCE^spont = MESF^medium/MESF^0h. Bcl-2 and Bax expression were assessed by flow cytometry as described in Figure 3 and were quantified in MESF units using calibration beads as fluorescence standards.