The Nurr1 gene encodes a member of the steroid-thyroid hormone- retinoid receptor superfamily. The encoded protein may act as a transcription factor. Mutations in this gene have been associated with disorders related to dopaminergic dysfunction, including Parkinson's. Nurr1 is a stem cell marker and cooperates with PITX3 to promote terminal maturation of murine and human embryonic stem cell cultures to a midbrain dopamine neuron phenotype. In addition, Nurr1 is involved in the regulation of corticotropin-releasing hormone (CRH), which may be linked to and associated with rheumatoid arthritis.