CXCR4 and acute respiratory distress syndrome: RvD1 reduced the expression of CXCL-12 mRNA in lung tissue, and promoted the expression of CXCR4 in neutrophils in the early stage of inflammation (24 h) while decreased the expression of CXCR4 in the later stage of inflammation (72 h), thereby regulating neutrophil aggregation in BALF and alleviating LPS-induced ALI (Yaxin et al., 2014).