The increased chelatable iron can induce the generation of ROS through Fenton reactions [34,35,36,37,38], we suggest that under DFO-induced iron-deficient conditions, the increased mitochondrial iron in triple-negative MDA-MB-231 breast cancer cells would induce the increase of mitochondrial ROS to activate the NF-κB and TGF-β signaling pathways, which is required for promoting cell migration. The gene discussed is TGFB1; the disease is breast cancer.