Nuclear receptors and transcription factors play a role in the development and maintenance of neurons that synthesize the neurotransmitter dopamine. The NURR1 gene encodes a 67-kDa member of the steroid-thyroid hormone-retinoid receptor superfamily. The orphan nuclear receptor NURR1 may function as a general coactivator of gene transcription and transcription factor. Mutations in Nurr1 have been associated with disorders related to dopaminergic dysfunction, including Parkinson disease, schizophrenia, and maniac depression. Misregulation of Nurr1 may be associated with rheumatoid arthritis.