The interaction of NM with α-synucleins may be a mechanism for this pigment to modulate neuronal vulnerability, and α-synuclein is over-expressed in individual melanized neurons, likely resulting in a vicious cycle of mutual promotion and eventual neuronal pathology in PD [68,69] Overall, these deposits are potentially neurotoxic, as these protein accumulations can interfere with the cell’s ability to prevent protein misfolding, revert misfolded proteins to normal, or eliminate misfolded proteins by degradation or autophagy, constituting the basis for pathological changes. Here, SNCA is linked to Parkinson disease.