The UCH-L1 and GFAP biomarkers, both of which were approved by the Food and Drug Administration for use in clinical decision-making among those with mild traumatic brain injury, had the highest accuracy for 1-year outcomes on days 2 and 3 after cardiac arrest, replicating the findings reported in a pilot study.7,8 The UCH-L1 biomarker had the highest sensitivity of the 4 biomarkers when optimizing specificity on days 2 and 3. Here, UCHL1 is linked to cardiac arrest.