Using a binary lineage-tracing approach (Acta2-tdT and Pdgfra-tdT) in two distinct animal models of lung fibrosis (bleomycin and Fra-2 Tg), we show anatomically preferential localization of αSMA- and PDGFRα-expressing cells at baseline and in fibrosis. This evidence concerns the gene ACTA2 and pulmonary fibrosis.