FGF1 and idiopathic pulmonary fibrosis: Faster migration by IPF fibroblasts may also be due to enhanced p-ERK1/2 signaling as stronger activation of p-ERK1/2 by FGF1 alone and heparin + FGF1 was also observed in IPF fibroblasts compared to donor, non-IPF fibroblasts used in this study.