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This biomarker is also known as:
  • ubiquitin carboxyl-terminal hydrolase isozyme L1,
  • PGP9.5,
  • UCH-L1,
  • PARK5,
  • PGP 9.5,
  • Neuron cytoplasmic protein 9.5,
  • ubiquitin carboxyl-terminal esterase L1 (ubiquitin thiolesterase),
  • PGP95,
  • Uch-L1,
  • Ubiquitin thioesterase L1,
  • ubiquitin C-terminal hydrolase,


PGP9.5, also called Ubiquitin-protein hydrolase (UCHL1), is a member of a gene family whose products hydrolyze small C-terminal adducts of ubiquitin to generate the ubiquitin monomer. Expression of UCHL1 is highly specific to neurons and to cells of the diffuse neuroendocrine system and their tumors. This enzyme is a thiol protease that recognizes and hydrolyzes a peptide bond at the C-terminal glycine of ubiquitin. Oxidation of Met-1, Met-6, Met-12, Met-124 and Met-179 to methionine sulfoxide, and oxidation of Cys-220 to cysteine sulfonic acid have been observed in brains from Alzheimer disease (AD) and Parkinson disease (PD) patients. PGP9.5 has been proposed as a marker with a potential role in carcinogenesis.


QA State: Accepted
Type: Protein
Short Name:


The following organs have data associated with this biomarker…



Phase: Three
QA State: Under Review


PGP9.5 antigens were found to be targets of autoantibodies in newly diagnosed subjects with lung cancer. PGP9.5 is also highly expressed in non-small lung cancer cell line H157, having high invasive potential, and the expression of PGP9.5 in tumor cells enhances their invasive potential in vitro and in vivo.

Performance Comment

The findings of this study show autoantibodies to UCHL1 (PGP9.5) may have diagnostic utility in conjunction with an imaging modality in symptomatic patients.

Supporting Study Data

The following studies/protocols provide evidence supporting UCHL1 indications for the Lung…

No supporting studies or protocols found.

Organ-Specific Protocols

No organ-specific protocols defined.

Organ-Specific Publications

Organ-Specific Resources

No organ-specific resources defined.


No associated studies or protocols found.


Mutation Statistics

Gene Name: UCHL1
UniProt Accession #: P09936
Mutated Sites Count: 37
Associated Pubmed ID Count 10
CancerDO Count 21
Affected Protein Function Sites Count: 5

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