Serum ubiquitin C-terminal hydrolase L1 (UCH-L1) has been proposed as a biomarker of traumatic brain injury (TBI).  

PGP9.5 rises within 1 hour of onset, reaches its peak at 8 hours, and can last up to 1 week after trauma. 

PGP9.5 can identify patients with intracranial lesions detected by CT and patients who need surgical treatment.