GSE induced annexin V/PI-based apoptosis in Ca9-22 cells. Cells were treated with indicated GSE concentrations (0–400 μg/ml) for 24 h. (A) Histograms of representative annexin V-FITC profile in GSE-treated Ca9-22 cells. (B) Quantitative analysis for the apoptotic cells (%). Apoptosis was counted at the intensity of right gated region in (A). Data, mean ± SD (n = 3). Treatments with the same capital letter are nonsignificant.