Fig. 6. Relationship between the extracellular-signal-regulated kinase (ERK)5 inhibitor response to TGF-β1-stimulated fibroblast bioactivity in vitro and biomarkers of lung fibrosis. (A-D) Comparison of the relationships between suppression of TGF-β1-induced gel contraction by BIX02189 and serum KL-6 (A) and SP-D (B) levels; and TGF-β1-induced migration and KL-6 (C) and SP-D (D) levels. Closed triangles and squares indicate lung fibrosis subjects with nonspecific interstitial pneumonia, and usual interstitial pneumonia patterns, respectively. Each symbol represents one patient.