FGFR1 and idiopathic pulmonary fibrosis: Given the strong expression of FGF1 and FGFR1/2/3/4 in regions of usual interstitial FF, as well as their co-localization with the migratory marker Fascin, and the myofibroblast marker α-SMA, the effect of exogenous FGF1 on IPF lung fibroblasts was addressed.