Figure 3. Human retinoblastoma (Y79) cells stained with annexin V and propidium iodide (PI) showing the different stages of apoptosis. A, B, and C are control groups. D, E, and F are 1 μM gossypol. G, H, and I are 10 μM gossypol. J, K, and L are 20 μM gossypol cultures. Scale bar is 50 μm.