Annexin V-PE labelling of MCF-7aro cells treated with 3a and 4a in comparison to control. Cells were stained with annexin V-PE and 7-AAD and analysed by flow cytometry. Compounds 3a and 4a (gray filled histograms) induced an increase in annexin V binding in MCF-7aro cells, in comparison to 9.2% of the control (medium containing 1 nM T, open histograms). Numbers in histograms are percent of annexin V-positive cells after treatment with the compounds. The histograms correspond to cells gated for negative 7-AAD staining. Data are representative of triplicate cultures and the figure is representative of three independent experiments.