CD4 and idiopathic pulmonary fibrosis: The percentage of all CXCR4+ cells in 16 IPF patients was significantly lower compared to 9 NDC (mean 75% vs 53%, p = 0.004) (Fig. 1a), with fewer CXCR4+/CD4+ and CXCR4+/CD8+ cells in IPF patients than NDCs (Fig. 1c, d).