Moreover, bronchoalveolar lavage fluid cells obtained from IPF patients during the onset of the disease produced higher levels of IL-1RA, CCL18, and other M2-related chemokines than cells obtained from the same patients outside the onset of the disease, and the higher the content of CCL18, the higher the seizure (Schupp et al., 1932). This evidence concerns the gene CCL18 and idiopathic pulmonary fibrosis.