CD4 and idiopathic pulmonary fibrosis: The results showed that the correlations between infiltrating immune cells in IPF patients with a high proportion of ATII-CCL20 were stronger, such as positive correlations between natural killer T cells, activated CD8 T cells, effector memory CD8 T cells, and activated CD4 T cells (Fig. 6B), while the correlations between infiltrating immune cells in IPF patients with a low proportion of ATII-CCL20 was weaker (Fig. 6C).