To explore the potential relevance of our findings in the gp130757F mouse model to human IPF, we first confirmed that excessive Stat3 activation in fibrotic lungs of bleomycin challenged gp130757F mice was dependent on IL-6 by monitoring expression of the bona fide Stat3 target gene Socs3 (Kidder et al, 2008; Snyder et al, 2008). Here, SOCS3 is linked to idiopathic pulmonary fibrosis.