UCHL1 and Stroke: However, a clinical study reported that serum UCH-L1 within 4 and 6 h after symptom onset was higher in HS patients than in IS patients and stroke mimics (SM), respectively (14); and in a single-center study of hyperacute IS, the area under the receiver operating characteristic curves (AUCs) of serum UCH-L1 for distinguishing IS patients from controls and IS from HS patients within 4.5 h after symptom onset were 0.64 and 0.62, respectively (15).