In contrast to these studies, treatment with Sigmar1 antagonists (NE 100) and Sigmar1 null mice showed reduced 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced dopaminergic neurons death and parkinsonism by suppressing N-methyl-d-aspartate receptor (NMDAr) function and dopamine transporter (DAT) expression (Hong et al., 2015). This evidence concerns the gene SLC6A3 and Parkinson disease.