CXCR4 and pulmonary fibrosis: In addition, chemokines also play a part in the fibrotic process of various injury models, for example, theCXCL12-CXCR4 chemokine axis is involved in liver fibrosis (Qin et al., 2018), and CCL2 is involved in pulmonary fibrosis in lung injury (Li et al., 2013).