C) and D) STAT3 knockdown in BCE cells. BCE cells were transfected with siNegative and siRNAs targeting STAT3. qRT-PCR were performed to examine STAT3 mRNA levels. STAT3 level in siNegative was set as 1. Data from three independent experiments were averaged and are presented in C. In D, cells transfected with siRNAs were treated with LIF (10 ng/ml) or vehicle for 15 minutes. Whole-cell lysates were subjected to Western blotting with the indicated antibodies. Data information: Bars and error bars represent mean ± SD. All experiments were carried out in three independent studies. Two-way ANOVA was used as statistical test. 