This study showed that in patients with CVD–ILD, IPAF, and IPF, the BALF levels of CXCL9 and CXCL10 were correlated with increases in A–aDO2 and BALF lymphocytes% and that serum levels of CXCL9, CXCL10, and CXCL11 were correlated with increases in BALF lymphocytes%, CRP levels, and A–aDO2. This evidence concerns the gene CXCL9 and idiopathic pulmonary fibrosis.