Previous studies using recombinant chemokines reported that both CCL2 and CCL7 can synergise with CXCL8 to enhance neutrophil migration, with CCL7 being more effective than CCL2.38, 39 Our data confirm the synergistic effect between these chemokines and highlight its potential importance in the ARDS disease setting. Here, CCL2 is linked to acute respiratory distress syndrome.