Since UWA-101 is the first dual SERT/ DAT inhibitor to be tested in PD models, it is hard to generalise but, we propose that, in order to employ monoamine re-uptake inhibitors, in combination with L-DOPA, to increase duration of ON-time without adversely affecting dyskinesia, it might be necessary to antagonise both the SERT and DAT. The gene discussed is SLC6A4; the disease is drug-induced dyskinesia.