An iron chelator with antiproliferative effects; inhibits in vitro proliferation of SK-N-MC neuroepithelioma, SK-Mel-28 melanoma, and MCF-7 breast cancer cells (IC50s = 30, 60, and 60 nM, respectively); increases mobilization of 59Fe from SK-N-MC cells and M109 mouse lung carcinoma cells (25 and 1 μM, respectively); enhances cytotoxicity in several multidrug resistant human cancer cell lines following transport to lysosomes by P-glycoprotein; inhibits M109 tumor growth in mice, reducing tumor weight to 47% of control values (0.4 mg/kg); reduces tumor size and weight in an oral squamous cell carcinoma mouse xenograft model (0.5 mg/kg),