Fig. 3. Stronger STAT activation in BW5147 cells overexpressing the IL-9R. BW5147 and BW-hIL9R cells were stimulated with murine IL-9 and hIL-9, respectively (500 units/ml), for the indicated periods of time. Alternatively, BW5147 cells were incubated with IFN-{gamma} (500 units/ml). Cells were lysed directly in sample buffer and loaded (105 cells/well) onto an 8% polyacrylamide gel. Phosphorylation of STAT1, STAT3, or STAT5 was visualized by Western blot with specific antibodies (New England Biolabs), according to the manufacturer’s instructions. As a control, blots were reprobed with an anti-actin antibody (data not shown). Similar results were obtained in three independent experiments.