GFAP and Parkinson disease: We measured the gene expression of Tyrosine Hydroxylase (TH; dopaminergic neuronal marker), Neuronal Nuclei (NeuN; neuronal marker), Glial Fibrillary Acidic Protein (GFAP; astrocyte marker), and Ionized Calcium-binding Adapter Molecule 1 (Iba1; microglial marker) in PD and controls.