The cytotoxic activity of TfR-lytic hybrid peptide: (A) Twelve cancer cell lines were cultured with various concentrations of TfR-lytic hybrid peptide or lytic peptide (0-30 μM) for 72 h, and cytotoxic activity was assessed using WST-8 reagent. (B) Two normal cell lines were cultured with various concentrations of peptides (0-60 μM) for 72 h and cytotoxic activity was assessed. Absorbance values obtained with untreated cells were set at 100%. Black and white squares indicate TfR-lytic hybrid peptide and lytic peptide, respectively. Data are represented by means ± SD (bars) from triplicate determinations.