(a–d) Gating strategy for isolation of fibroblasts, epithelial and endothelial cells from the lungs of mice 14 days post-aerosolized instillation of bleomycin (Bleo) or PBS. (a) Total single-cell suspensions (P1) were gated to exclude doublets (P2) and CD45+ cells (P3). (b) Fibroblasts (PDGFRα+, EPCAM−, CD31− and CD45−), (c) epithelial cells (EPCAM+, PDGFRα−, CD31− and CD45−) and (d) endothelial cells (CD31+, PDGFRα−, EPCAM−, CD45−) were sorted from the P3 population. The expression of p16, SASP genes (Mcp1, Pai1, Tnfα, Mmp10, Mmp12) and fibrotic genes (Col1a1 and Tgfβ) were quantified by RT–PCR and are expressed relative to Hprt levels in sorted populations of (e) fibroblasts, (f) epithelial cells and (g) endothelial cells (mean±s.e.m.; PBS n=8 (grey), Bleo n=6 (red); t-test, ***P<0.0005, **P<0.005, *P<0.05, ¥P≤0.07 and #P≤0.1.).