The concentrations of PDGF-AA, PDGF-BB, FGF-2, VEGF and M-CSF were significantly increased in PF-ILD lungs compared to donor lungs (PDGF-AA 93·0 pg/ml [±97·2] vs. 37·5 pg/ml [±35·4], p < 0·001; PDGF-BB 102·5 pg/ml [±78·8] vs. 61·9 pg/ml [±47·0], p < 0·001; FGF-2 1442·4 pg/ml [±426·6] vs. 1201·7 pg/ml [±535·2], p = 0·009; VEGF 40·6 pg/ml [±20·1] vs. 24·9 pg/ml [±29·5], p < 0·001; and M-CSF 25526 pg/ml [±24,799] vs. 6120 pg/ml [±7245], p < 0·001). This evidence concerns the gene CSF1 and interstitial lung disease.