NR4A2 and Parkinson disease: 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is used to simulate PD conditions in animal models (Wu et al., 2022) and lower Nurr1 expression increases the mesencephalic DAergic neurons vulnerability to MPTP in Nurr1+/– mice (Le et al., 1999).