COPD patients: High numbers of iNKT cells and IL-13+ CD68+ macrophages in lung tissues from COPD patients Sendai virus infection model: 1. IL-13+ macrophages contribute to lung inflammation induced by viral infection 2. Lower number of IL-13+ macrophages in CD1d1−/− or Traj18-deficient mice. This evidence concerns the gene TRAJ18 and viral infectious disease.