Mesencephalic Astrocyte-Derived Neurotrophic Factor (MANF) and Conserved Dopamine Neurotrophic Factor (CDNF) are members of a novel, evolutionarily conserved neurotrophic factor family with specific protective properties on dopaminergic neurons, as shown in 6-hydroxydopamine (6-OHDA) animal models of PD [50]. Here, CDNF is linked to Parkinson disease.