F16 is a small, cationic, lipophilic molecule which binds preferentially to mitochondrial membranes and disrupts their function. F16 was discovered in high throughput screens for tumor inhibitors, where it was found to induce apoptosis in HER-1/EGFR-expressing breast carcinoma cell lines. In addition to being a potential antitumor agent, F16 is an easily visualized fluorescent molecule which can also be used to visualize mitochondria under confocal microscopy. The mechanism of apoptosis induction by F16 is believed to be through disruption of the mitochondrial transmembrane potential.