TGFB1 and fibrosis: The emergence of pro-fibrotic FLS subpopulations (Fib_Cmss1 and Fib_Tnc) with enriched ECM-receptor interaction, PI3K-AKT, and TGF-β signaling pathways (Figures 8C–F) underscores the role of fungal components in driving synovial fibrosis.