(A) Differential gene expression of hormone receptors in fibroblasts compared to other cells in iSGS patients as determined by scRNAseq. iSGS fibroblasts showed significantly increased ESR1 and PGR expression (both P < 0.001), while demonstrating no ESR2 expression. Bar represents mean; error bars represent SEM; dots show individual patients. ****P < 0.001; ns = not significant (P > 0.05). (B) Representative histograms of fibroblast hormone receptor protein expression, confirming expression data for ER-α, ER-β, and PR in iSGS airway scar. ER-α (Abcam Alexa Fluor® 488); ER-β (Abcam PE); PR (Abcam Alexa Fluor® 647). Red = negative control; Blue = receptor expression. (C) Graph depicting the mean fluorescence intensity of ER-α, ER-β, and PR within fibroblasts isolated from airway scar of 5 iSGS patients via flow cytometry. Bar represents mean; error bars represent SEM; dots show individual cell lines.