HMGB1 and cystic fibrosis: Although the difference in the levels of airway HMGB1 between CF and WT mice in the absence of PA infection was not statistically significant, after PA infection, the CF mice had significantly elevated levels of airway HMGB1 comparing to WT mice infected with PA (1.71 ± 0.29 AU in CF vs 1.00 ± 0.02 AU in WT, p < 0.05) (Fig. 5A).