In addition, the neuroprotective activityof mGDNF (produce from E. coli or HEK293) was studied in the MPTP model of Parkinson’s disease in vivo, the tyrosine hydroxylase activity of substantia nigra pars compacta was assessed, and the motor activities of mice, treated with GDNF isoforms, was compared. The gene discussed is GDNF; the disease is Parkinson disease.