IL6 and systemic inflammatory response syndrome: For patients with low SIRS scores (< 2, N = 341), IL-6 was demonstrated to have the highest performance among all clinical scores or biomarkers in predicting 28-day mortality (N = 13; 3.1%; AUC = 0.859), followed by CRP and IL-10 (AUC = 0.771 and 0.762), indicating a comparable performance in relation to other clinical scores and biomarkers (Table S9).