HMGB1 and idiopathic pulmonary fibrosis: Our findings showed that serum levels of bound HMGB1, mH2A1.1, 5mC, H3K9Ac, and H3K27Ac were significantly lower in IPF patients than in HS (p < 0.001, p < 0.001, p < 0.01, p < 0.001, and p < 0.0001, respectively).