LMX1A and Parkinson disease: Separately, using a proteomics-based approach, Fathi et al., showed that LMX1A+ dopaminergic progenitors express both PSA-NCAM and Contactin-2 (CNTN2) on their surface and that transplantation of CNTN2+ progenitors enhanced dopamine release in the host brain compared to unsorted cells, along with associated improvements in PD symptoms in rodents [15].