In the present study, multivariate logistic regression analysis revealed that the percentage of S100A9+CD163− cells (Gate 1) and S100A9−CD163+ cells (Gate 4) was a diagnostic factor for discriminating IPF from iNSIP, independently from the smoking status, in addition to age, sex, and %FVC. The gene discussed is CD163; the disease is idiopathic pulmonary fibrosis.