Caffeic acid also plays a significant protective role in PD by decreasing the level of α-synuclein level [259] while the caffeic acid phenylethyl ester showed therapeutic potential against Huntington’s disease by reduction of striatal damage, immunoreactivity to glial GFAP, and lymphocyte common antigen (CD45) (markers of astrocyte and microglia activation) [260]. The gene discussed is GFAP; the disease is Parkinson disease.