CXCL9 and interstitial emphysema: Later, by performing transcriptomic studies we corroborated these findings by demonstrating that activation of NF-kB and MAPK pathways in PIE cells results in an increased expression of several chemokines including CCL4, CCL5, CCL8, CCL20, CXCL2, CXCL5, CXCL9, CXCL10, CXCL11, CSF2, as well as complement and coagulation factors (27).