FN1 and idiopathic pulmonary fibrosis: We observed an increase in fibronectin 1 (FN1) and collagen 1 (COL1A1) gene expression after the treatment with pirfenidone, suggesting that although evidence shows its anti-fibrotic effect in proliferative IPF fibroblasts39, our results suggest that pirfenidone was unable to reduce those fibrosis markers.