NR4A2 and Parkinson disease: A decrease in Nurr1 expression was also observed in neuroblastoma cell lines transfected with wild-type α-Syn [84] and in human PD [119], implicating this protein in the development and progression of synucleinopathies and prompting a search for clinically applicable agonists of Nurr1/RXR heterodimer as a PD therapy [120,121].