SLC6A3 and Parkinson disease: SH-SY5Y-derived dopaminergic neuron-like cells not only express DJ-1 protein and TH, which are extensively related to the early onset of PD, but also the dopamine transporter (DAT), which regulates dopamine homeostasis, incorporates MPP+, and can be utilized in MPP+-induced neurotoxicity [38, 39].