Deng X, Liang Y, Lu H, Yang Z, Liu R'en, Wang J, Song X, Long J, Li Y, Lei D, et al. Co-Transplantation of GDNF-Overexpressing Neural Stem Cells and Fetal Dopaminergic Neurons Mitigates Motor Symptoms in a Rat Model of Parkinson's Disease. PLoS One. 2013;8(12):e80880.