CXCL12 and idiopathic pulmonary fibrosis: Mirroring data shown in Fig. 4, the proportion of single positive CXCR4 cells was increased in lung tissue from IPF compared to NDC (effect size 1.378, p = 0.026) (Fig. 5b) and there was no difference in the proportion of CD45+ (Fig. 5c) or CXCL12+ cells (Fig. 5d).