E47 can rescue the downmodulation of the BCR induced by CA-STAT5b. (A) E47 expression is repressed upon STAT5bER activation as assessed by real-time RT-PCR analysis (n = 3). (B) Flow cytometric analysis of the BCR determined by the surface expression of kappa and lambda light chains. PB B cells double transduced with CA-STAT5b plus control GFP (■) or CA-STAT5b plus E47 (○) cultured on CD40L-L cells plus IL-2 and IL-4. Data represent means (± SD) of 3 independent experiments.