DPT and neoplasm: A key criterion for the anti-tumor efficacy of the DpT group of thiosemicarbazones is their ability to form redox active Cu complexes that potently generate ROS, which results in lysosomal membrane permeabilization and apoptosis.25,26,28 As such, it was important to assess the redox activity of the Dp4e4mT ligand and its complexes to dissect the mechanism(s) of their anti-proliferative activity observed in Table 2.