JAK1 and pulmonary fibrosis: In pulmonary fibrosis, SHP2 has prevented macrophage M2 polarization and the subsequent development of pulmonary fibrosis.60 Chang et al. demonstrated that SHP2 activation promoted hyporesponsiveness to IFN- γ in TGF-β differentiated myofibroblasts, and that TGF- β-activated SHP2 was tightly associated with pulmonary fibrosis.56 The protective role of SHP2 may be attributed to its inhibitory action on IL-4 mediated JAK1/STAT6 activation.