Whereas the GP, like the SN, is known to be a “sink” for metals (e.g., Fe, Mn, Cu) [51]–[54] and is lack in transferrin-binding sites [55], it does not contain dopamine neurons, but it is vulnerable to iron-mediated (e.g., Hallervorden Spatz disease, PKAN and oxidative stress-related neuronal and glial damage such as that observed due to carbon monoxide toxicity [20]. Here, TF is linked to pantothenate kinase-associated neurodegeneration.