Cytokines: IL-4, IL-5, IL-9, IL-13, IL-17A, IL-22, TGF-β, TNF-α, et al. ↑ Wynn (2008); Desai et al. (2018). Activating PI3K/AKT, TGF-β/Smad, ERK1/2 and JAK/STAT pathways. Activating fibroblasts and myofibroblasts Deng et al. (2023). Extensively promotes ECM production and collagen deposition Deng et al. (2023). Extracellular matrix proteins, types I and III collagen and fibronectin increased in ILD Roberts et al., 2003. Here, IL9 is linked to interstitial lung disease.