TPEN (TPEDA) is a specific cell-permeable heavy metal chelator that induces apoptosis in NB4 cells via negatively regulating intracellular NO and Zn2+ signaling. TPEN (TPEDA) may be a potential therapeutic strategy for APL (acute promyelocytic leukemia).TPEN induces DNA damage and increases intracellular ROS production and also inhibits cell proliferation.