TF and Alzheimer disease: The TF C2 variant is reported to be a risk factor for AD, in synergy with the p.Cys282Tyr (rs1800562) allele of the Homeostatic Iron Regulator (HFE) gene: the combination of TF C2 and the HFE p.Cys282Tyr might lead to an excess of redox-active iron and eventually the generation of oxidative stress in the preclinical phase of AD [48,49,50].