HMGB1 and idiopathic pulmonary fibrosis: A connection to IPF is suggested by the finding that endogenous TLR4 ligands such as high mobility group box 1 (HMGB1) (Park et al., 2004; Li et al., 2014), tenascin-C (Midwood et al., 2009; Carey et al., 2010; Bhattacharyya et al., 2016), S100 protein (Park et al., 2004) and hyaluronan fragments (Jiang et al., 2005) are enriched in IPF BAL and lung tissues (Huebener and Schwabe, 2013).