GDNF and Parkinson disease: Also, additive effects of GDNF with TGF-β1, given by osmotic minipumps to the dorsal striatum (Gonzalez-Aparicio et al., 2010), and of MANF with CDNF, given as a special lentiviral gene construct to the SN (Cordero-Llana et al., 2015), were reported in the 6-OHDA model of PD in rats.