CCL21 and idiopathic interstitial pneumonia: Up-regulated chemokines and receptors, mainly linked to inflammatory activities (CCL5, CCL7, CCL8, CCL11, CCL13, CCL18, CCL19, CCL21, CCL22, CCL24, CXCL6, CXCL10, CXCL12, CXCL13, CXCL14, CXCL17, CCR5, CCR6, CCR7, and CCR8), that contribute to leukocyte recruitment and chronic inflammation in IPF (Figure 2 and Figure 3A,B).