In a subgroup of OHCA patients with EEG data (not analysed in IHCA due to limited data), the prognostic performance of routine EEG (median [IQR] 75 [59-98] h after cardiac arrest) was improved by adding NfL at 12 h (AUROC 0.77 to 0.90, p < 0.001) or 48 h (AUROC 0.74 to 0.97, p < 0.001), but not by NfL on admission (Additional file 1: Table S6). The gene discussed is NEFL; the disease is cardiac arrest.