DRD2 and Parkinson disease: Since the A2AR-D2R heteromer is an important drug target for several basal ganglia-related diseases (such as schizophrenia and PD)52,54 and because ST8SIA3 is capable of regulating the population of A2AR-D2R heteromers in the striatum, our findings highlight the importance of ST8SIA3 as a new drug target.