Furthermore, the Fernández-Suárez research group observed increased immunoreactivity of microglia and astrocytes in the SNpc and striatum, along with elevated expression levels of transforming growth factor-β (TGF-β) and glial cell line-derived neurotrophic factor (GDNF) in the striatum of mice with induced parkinsonism [43]. The gene discussed is GDNF; the disease is Parkinson disease.