FST and idiopathic pulmonary fibrosis: In the IPF group we found statistically significant correlations between concentrations of Ang-2 and IL-8 (r = 0.62, P < 0.01), follistatin and PECAM-1 (r = 0.83, P < 0.0001) and PDGF-BB and VEGF (r = 0.7, P < 0.01).