Other evidence for the strong association between RXR and PD, further ascertaining the potential role of VA in curing PD, includes the ability of RXR to dimerize with NURR1, an orphan nuclear receptor expressed in dopaminergic neurons, so as to co‐regulate NURR1 target genes required for survival and maturation of dopaminergic neurons.70 This evidence concerns the gene NR4A2 and Parkinson disease.