SMAD3 and idiopathic pulmonary fibrosis: Consistent with this possibility, and in direct contrast with the actions of MKP1 demonstrated in this work, a previous study revealed that DUSP10/MKP5 was crucial for TGF-β–induced SMAD3 activation in lung fibroblasts and was upregulated in IPF fibroblasts, and that its global deletion mitigated bleomycin-induced pulmonary fibrosis (72).