Effect of IKKε siRNA on apoptosis of breast cancers. (a) SK-BR-3 cells or (b) MCF-7 cells were transfected with siR-1, siR-8, and scrambled siRNA at 50 nM. Seventy-two hours after transfection, cells were stained with Annexin-V-FITC and propidium iodide followed by flow cytometry. The percentage of early apoptotic (right bottom), late apoptosis (right top), and necrotic cells are shown. Three independent experiments were conducted. NC, negative control siRNA.