A decrease in serum Tf has previously been reported in PD,17 whereas a prior paper observed no difference in Tf in PD or AD SN, which also reported no change in iron compared with elderly controls.18 We examined SN from post-mortem PD subjects (n=10) and controls (n=10), and found the loss of Tf in disease (−35%, P=0.021; Figures 1a and b), accompanying iron elevation (+42%, P=0.021; Figure 1a) as previously described.8,10 The loss of Tf could restrict iron flux in this nucleus, and contribute to iron deposition. This evidence concerns the gene TF and Alzheimer disease.