A, B: Effect of FIP3 silencing on Rac1 expression. Jurkat cells were transfected with control, FIP3.1 or FIP3.2 siRNA. Three days later cells were lysed and the expression of FIP3, Rac1 and β-tubulin analyzed by western blot. The intensity of bands corresponding to FIP3 and to Rac1 was quantified by ImageJ and normalized to the β-tubulin band used as loading control. The mean ± SD of the percentage of band intensity in silenced cells with respect to controls of three independent experiments is shown. 