Conversely, SDF-1 inhibition impairs alveolar epithelial cell spreading and delays resolution of permeability after lung injury [29] and agonism of the SDF-1 receptor, CXCR7, prevents epithelial damage, promotes alveolar repair and reduces bleomycin-induced pulmonary fibrosis [30]. This evidence concerns the gene CXCR4 and pulmonary fibrosis.