Effects of LY 294002 on ROS accumulation. Serum-starved cells were pretreated with LY 294002 (10 μM) for 30 min and then treated with HGF (10 ng/ml). The intensity of DCF fluorescence was measured with flow cytometry (A). Mean fluorescence intensity was obtained from 3 independent experiments and plotted (B). Representative data from three independent experiments are shown. Values are the means ± SD of three independent experiments. Statistical significance was estimated by Student's t-test (*, p < 0.05; **; p < 0.01).