The similar expression pattern of gremlin-1 and BMP4 is reproduced even in IPF lung-derived (myo)fibroblasts [11], implying a common role for myofibroblasts in fibrotic lungs in inhibiting BMP4 signaling, probably via gremlin-1 autocrine activity. The gene discussed is GREM1; the disease is idiopathic interstitial pneumonia.