HMGB1 and bacterial pneumonia: Although HMGB1 levels only tended to increase 6 hours after induction of S. aureus pneumonia, anti-HMGB1 reduced protein leak and lung edema at this time point, which is in accordance with results obtained during Gram-negative pneumonia[13,15,16], In contrast, we did not find a role for HMGB1 in neutrophil recruitment, which at least in part may be explained by differential pattern recognition receptors and integrins involved in attraction of neutrophils to the lungs by Gram-negative and Gram-positive stimuli[6].