CXCL12 and idiopathic pulmonary fibrosis: The proportion of single positive CXCR4+ cells was increased in patients with IPF compared to NDC donors (effect size 1.494, p = 0.007) (Fig. 4b), but there was no difference in the proportion of cells expressing e-cadherin+ or CXCL12+ alone between the IPF and NDC groups (Fig. 4c, d).