Moreover, IFNγ levels are increased in Parkinson’s disease patients67 and IFNγ-deficient mice displayed attenuated 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced substantia nigra pars compacta dopaminergic cell loss68 consistent with a role of IFNγ in neurodegeneration. The gene discussed is IFNG; the disease is Parkinson disease.