CASP3 and cancer: To determine whether the cytotoxic effect of TfR-lytic hybrid peptide was due to the cell death including an apoptotic cell death, cancer T47D and normal PE cells were treated with TfR-lytic peptide (10 μM) or lytic peptide alone (10 μM) for 3 h, and results were confirmed by annexin V-PI and caspase 3&7-PI staining using flow cytometry.