This observation aligns with the findings of a large meta-analysis investigating neurological outcome after cardiac arrest utilizing neurobiomarkers for prognostication.20 When stratifying patients based on higher or lower admission free-hgb, we found that patients with high free-hgb after OHCA had longer time to ROSC and higher NSE concentrations after 48 h compared to the group with low free-hgb, however, no group difference in NfL was seen. The gene discussed is ENO2; the disease is cardiac arrest.