UCHL1 and Parkinson disease: By oxidation, not only the generation of ROS, including hydrogen peroxide, superoxide anion, and hydroxyl radicals, but also the generation of DAQ, which plays a crucial role in dopamine-related toxicity to DA neurons by modifying genes associated with PD, such as α-synuclein (α-syn), parkin, DJ-1, and ubiquitin C-terminal hydrolase L1 (UCH-L1), degenerate DA neurons.