Ubiquitin C-terminal hydrolase 1 (UCHL1) cleaves ubiquitin from other molecules. Genetic knockout of UCHL1 in mice results in a motor neuron degeneration similar to the spontaneous gracile a, Xenopus/Amphibian,onal dystrophy (gad) mutant mice. Point mutations in the UCHL1 gene are associated with some forms of human Parkinson's disease. Since UCHL1 is heavily e, Xenopus/Amphibian,pressed in neurons, it is released in large amounts following injury or degeneration. The detection of UCHL1 in CSF and other bodily fluids can be used as a biomarker.