PDGFRB and pulmonary fibrosis: Elevated platelet-derived growth factor receptor (PDGFR) expression is detected in human heart disease, pulmonary fibrosis, and kidney fibrosis [6]–[8], and blocking PDGFR signaling decreases collagen deposition after myocardial infarct, in pulmonary fibrosis, and in kidney fibrosis [9]–[11].