Dysfunctions of both D3R and nAChR have been reported to play a role in the development of several disorders, including PD and addiction, and the discovery of the D3R-nAChR heterodimer may open the way to the design and development of novel drugs capable to positively modulate this heterodimeric complex, to support DA neuron plasticity and survival and to protect DA neurons from toxic damage. Here, CHRNA4 is linked to Parkinson disease.