GREM1 and idiopathic interstitial pneumonia: According to our published mouse microarray dataset (GSE111043), gremlin-1 mRNA (Grem1) was significantly upregulated, while BMP4 mRNA was downregulated in bleomycin-induced lung myofibroblasts compared with steady-state fibroblasts (Fig. 2a), which is consistent with previous human data comparing IPF (myo) fibroblasts with normal fibroblasts [11].