When testing for specificity of the above findings by controlling for each other impact in dyskinesia- and parkinsonism-related neurotransmitter systems using multiple linear regression, we found that among both significant associations between dyskinesia-related grey matter alterations and dopaminergic neurotransmitter systems, the dopamine transporter survived at a marginal significance level (P = 0.070). The gene discussed is SLC6A3; the disease is drug-induced dyskinesia.