NR4A2 and Parkinson disease: A recent report also links Nurr1 with alpha-synuclein, a key protein in PD pathogenesis, and describes that alpha-synuclein over-expression by an unidentified mechanism promote Nurr1 degradation [35] linking mesencephalic Dopamine (mesDA) neurons maintenance and survival by Nurr1 and the expression levels of alpha-synuclein.