TF and Parkinson disease: Involvement of Tf in PD was studied by Ayton et al. (2016), who reported that the tissue concentration of Tf is decreased in the substantia nigra of PD patients (Ayton et al. 2016), possibly due to Tf trafficking of iron away from the tissue, mis-localisation of Tf (Gille and Reichmann 2011; Ayton et al. 2016), or decreased production of Tf (Pfeiffer and Looker 2017; Dignass et al. 2018).