Finally, a large screening study (> 1200 drugs) from 32 sporadic ALS human iPSC lines showed that ropinirole, a dopamine (D2) receptor agonist used to treat Parkinson’s disease motor symptoms, reverses their identified neurite length, cytotoxicity and abnormal protein aggregations phenotypes, by reducing the elevated reactive oxygen species, implicating ropinirole’s non-canonical effects on mitochondrial pathways [36]. This evidence concerns the gene DRD2 and Parkinson disease.