At the same time, tumor cells strictly regulate the expression of ferritin, protein made up of ferritin heavy chain (FtH1), provided with ferroxidase activity, and ferritin light chain (FTL), to properly store the intracellular free iron and, thus, control its participation in the Fenton reactions-mediated production of reactive oxygen species (ROS) (Pfeifhofer-Obermair et al., 2018; Morales and Xue, 2021; Sacco et al., 2021). The gene discussed is FTH1; the disease is neoplasm.