TGFB1 and pulmonary fibrosis: Interestingly and relevant to RA-ILD pathology, in bleomycin-induced pulmonary fibrosis mouse models, the Jak inhibitor baricitinib attenuated disease severity via inhibition of the TGF-β1/non-Smad and TGF-β1/JAK/STAT signaling pathways, therefore limiting fibroblast activation and epithelial cell injury, respectively (130).