CCR7 and idiopathic interstitial pneumonia: Focal interstitial CCR7 protein is expressed in fibrotic surgical lung biopsies (SLBs) but not in normal margins, and these CCR7-positive (CCR7+) areas in IPF SLBs lack markers for collagen-producing fibrocytes (a distinct population of blood-borne cells exhibiting potent immunostimulatory activities), indicating that focal CCR7 expression may reveal idiopathic injury sites and inappropriate activation of resident fibroblasts [96,97,98].