CXCR4 and idiopathic pulmonary fibrosis: To further characterize the isolated primary cells from UIP lungs with mesenchymal stem properties, we stained the cells for HGF and CXCR4 in vitro (Figure 5c, 5d) and show that the isolated cells have similar properties as the described HGF-expressing cells in UIP in vivo, that is are co-staining for HGF and CXCR4 (Figure 5c and 5d).