Selective PPAR-γ agonists, such as rosiglitazone and pioglitazone, improve cognitive performance and reduce amyloid-β in patients with mild AD [113,114], and produce promising behavioral and neuroprotective effects in animal models of Parkinson's disease [115], amyotrophic lateral sclerosis [116] and Huntington's disease [117]. This evidence concerns the gene PPARG and Alzheimer disease.