Given that MAP3K19 is expressed by multiple pro-inflammatory cell types in the lung and that it can modulate TGF-β-mediated signal transduction and gene transcription, we wanted to ask whether inhibition of MAP3K19 could influence the development of pulmonary fibrosis in vivo, using a murine model of bleomycin-induced pulmonary fibrosis. The gene discussed is MAP3K19; the disease is pulmonary fibrosis.