SNCA and Parkinson disease: First, a toxic loop involving ferroptosis, α-synuclein, and neuromelanin exists in the PD microenvironment, yet this study has not clarified the bidirectional regulation between ferroptosis and α-synuclein oligomers—specifically, whether oligomers disrupt LIP homeostasis to trigger ferroptosis, or how lipid peroxidation products from ferroptosis accelerate protein aggregation.