SLC6A3 and Parkinson disease: Abnormalities in its function not only disrupt the lysosomal degradation pathway but also cause an imbalance in synaptic dopamine homeostasis by disturbing the cycling and localization of the dopamine transporter (DAT), ultimately leading to dopaminergic neuronal degeneration—a process that is particularly prominent in Parkinson’s disease (PD) models carrying the VPS35 D620N mutation (Huang et al., 2022; Mohan and Mellick, 2017).