Myofibroblast activation in ISG15-deficient cells. (A) Spatial expression and intensity levels of two myofibroblast markers (ACTA2 and COL5A1). (B) Relative expression of various myofibroblast markers for clusters 1 and 5 separated by sample biopsy. (C) Percentage of total spots that express TGFβ in the entire biopsy, within CD68⁺ spots only, and within myofibroblast cluster 5. (D) Significance of pathway enrichment for clusters 0, 1, 5, 3, 7, and 9 generated by MSigDB Hallmark 2020 and BioPlanet 2019 analysis from Enrichr. Adjusted P values are shown. (E) Relative RNA levels of myofibroblast markers (PDGFA, ITGB6, FGF2) following a 72-h treatment with 1,000 IU/ml IFNα2b, 10 ng/ml TGFβ, or both of WT and ISG15 KO lung epithelial cells (A549). (F) Percentage of cells undergoing EMT upon TGFβ/IFNα stimulation. (G) Relative RNA levels of myofibroblast markers (PDGFA, ITGB6, FGF2) following a 5-day treatment with 1,000 IU/ml IFNα2b, 10 ng/ml TGFβ, or both of WT and ISG15 KO fibroblasts. (H) ACTA2 (myofibroblasts) IHC for lesion 1 and lesion 3. P values were calculated with two-tailed t test. *P < 0.05.