Downmodulation of Bcl-2 expression is prevented by IL-2. PBMC treated with Leu3a/GAM were cultured in the absence or presence of IL-2 (30 U/mL) for 3 days. The percentages indicated in the figure are percentages of the Bcl-2 dim plus Bcl-2 negative cells. Values of statistical significance determined by paired t test are indicated (n = 6).