In the present study, we have, therefore, exposed SH-SY5Y cells (a neuroblastoma cell line with the robust expression of alpha-synuclein) to varying concentrations of DA over a period of 24 h with or without radical and quinone scavengers and measured cytotoxicity parameters as well as alpha-synuclein content and proteasomal activity. The gene discussed is SNCA; the disease is neuroblastoma.