Beyond cellular interactions, a number of technical parameters are likely to have an important role in cell-based therapy in PD, specifically issues of tissue procurement and preparation, such as the age and number of donor fetuses, graft dissection procedures, storage length and conditions, tissue dissociation before transplantation, or the use of ancillary neuroprotective strategies to increase graft survival (i.e., GDNF, lazaroids) [86, 87]. Here, GDNF is linked to Parkinson disease.