Phenethyl isothiocyanate (PEITC) induces cell death in breast cancer cells. (A) MDA-MB-231, (B) MCF-7 cells were treated with increasing concentrations of PEITC for 24, 48 and 72 h. Cell survival was measured with sulforhodamine B assay to estimate the IC50 values. The experiments were repeated at least three times with eight replicates in each experiment. (C) MDA-MB-231 and (D) MCF-7 cells were treated with or without PEITC (2.5, 5, 10, 15 μM) for 24 h. Cells were then collected and labeled with annexin V/fluorescein isothiocyanate (FITC). Cells that were positive for annexin or propidium iodide or both were measured using flow cytometry. Representative images are shown. Each experiment was repeated more than three times independently. *Statistically different when compared with control (P < 0.05).