P2RY6 and Parkinson disease: This has been demonstrated in vitro on neuronal SH-SY5Y cells (cell cultures used in the study of the molecular and cellular mechanisms of toxic substances contributing to the development of PD), whereby exposure to 1-methyl-4-phenylpyridinium (MPP+), a compound with toxicity to dopaminergic neurons, increases the density of P2Y6 whereas the administration of a receptor agonist enhances its toxicity.