CXCR4 and pulmonary fibrosis: Indeed, in vivo neutralization of CXCL12 resulted in reduced number of lung CD45+ Col1+ CXCR4+ fibrocytes and α-SMA-expressing myofibroblasts as well as reduced lung collagen content and attenuated pulmonary fibrosis by histologic morphometric analysis, but did not influence the number of lung neutrophils, macrophages, CD4 and CD8 T cells or NK cells [24].