The pulmonary diseases associated with increased levels of the soluble form of FasL include (see Table 2): interstitial lung diseases (ILDs) such as hypersensitivity pneumonitis [66], idiopathic pulmonary fibrosis (IPF) [67], asbestosis and interstitial pneumonia [4,6,66,68]. This evidence concerns the gene FASLG and idiopathic pulmonary fibrosis.