GREM1 and idiopathic pulmonary fibrosis: The changes in the grem1 mRNA expression levels during the process of human idiopathic pulmonary fibrosis (IPF) were analyzed using the Gene Expression Omnibus (GEO) database, and the expression of Grem1 in the group of patients with IPF was significantly higher than that in the healthy group (Fig. 3G), which indicated a role for Grem1 in pulmonary fibrosis.