However, it has not yet been explored if the neuroprotection afforded by A2AR antagonists in the context of PD is restricted to the prodrome and early PD when striatal synaptotoxicity is predominant, or if A2AR antagonists instead afford delayed neuroprotection, attenuating the dying-back mechanism that results in the delayed degeneration of the DA cell bodies in the substantia nigra. Here, ADORA2A is linked to Parkinson disease.