More specifically, we determined the concentrations of PDGF-AA, PDGF-BB, FGF-2, VEGF and M-CSF in whole lung homogenates from patients with PF-ILD of different aetiologies including IPF, SSc-ILD, other CTD-ILD, sarcoidosis and exposure related-ILD, and compared them to normal lung tissue. The gene discussed is CSF1; the disease is sarcoidosis.