SFXN3 and Parkinson disease: iTRAQ proteomics on synaptosomes from α-syn+/+ and α-syn-/- mice also revealed that α-syn interacts with sideroflexin 3 (SFXN3), a putative iron transporter of the IMM (Fleming et al., 2001; Li et al., 2010) which is important for maintenance of the synaptic morphology and neuromuscular junctions (Amorim et al., 2017) and that has been found down-regulated in substantia nigra of PD-affected patients (Simunovic et al., 2009).