Motivated by our finding of CMKLR1 mRNA expression by lung macrophages and BAL cells in fibrotic lung diseases, we performed an exploratory analysis to confirm histological evidence of CMKLR1 protein expression in the lungs of patients with IPF and other fibrotic lung diseases using an existing biorepository (table S1). The gene discussed is CMKLR1; the disease is idiopathic pulmonary fibrosis.