In whole lung homogenates, mean protein concentrations of PDGF-AA, PDGF-BB, FGF-2, VEGF and M-CSF did not show significant differences between the underlying ILD aetiologies (IPF, SSc-ILD and other ILD), except for VEGF, which was significantly higher in SSc-ILD compared to IPF measured by ANOVA (Fig. 4(a)–(e)). Here, FGF2 is linked to idiopathic pulmonary fibrosis.