HMGB1 and acute lung injury: A recent study reported that SIRT1 is involved in the inhibitory action of (d-Ala2)-dynorphin 1-6 (leytragin), a peptide agonist of δ-opioid receptors, upon high mobility group box 1 (HMGB1) secretion in the lungs of mice with lipopolysaccharide (LPS)-induced acute lung injury [79].