Many of these factors have been reported to be protective for nigrostriatal neurons in animal models of Parkinson's Disease, including GDNF, neurturin, CDNF, MANF, PDGF, FGF20 and PACAP (Lindholm et al., 2016, Voutilainen et al., 2017). The gene discussed is GDNF; the disease is Parkinson disease.