HMGB1 and systemic inflammatory response syndrome: However, the median (interquartile range) of the serum HMGB1 concentration was significantly higher (P = 0.01) in the SIRS subgroup [0.85 (0.12–1.85) ng/mL] than in the non-SIRS subgroup [0.05 (0.01–0.13) ng/mL].